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#21
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WEEKDAY()
Bob,
=A1 and format as General. As we said...... Thank you for being patient and putting up with me. I am very unfamiliar with dates, just starting. I did hear you - "......underlying value of a date is just the number of days since 1st Jan 1900...... when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559......" I registered the small pieces of info and I thought I understood. But when I tried to piece them together ...... Here's what has happened. I had a blank cell and I thought I saw the format as "general." Then I keyed in a date like 21/4/2008 into the cell and I saw the exact same thing as I had keyed in. ***I was under the impression that "general" was still the format***. I didn't recheck the format at that point. When I did, I noticed that it was changed from "general" to "date." This is why I don't know that "general" format can display the actual no. of days. So, this is what I have missed and you can tell how green I am. You may not want to, but Biff is right. 1st Jan 1900 was a Sunday, the 31st Dec 1899 was a saturday, which is day 7 to WEEKDAY. You get 7-Jan-00 because it is formatted that way, the underlying value is 7. When I read Biff's writeup, I found it very logical because I did agree that 1/1/1900 was a Sunday. But when I keyed in =WEEKDAY(0) ...... =WEEKDAY(--"1900/01/01"-1) returns 7. Ah, this is what I have missed from Biff's writeup and what I didn't do. Now, I am totally convinced. Bob, you are such a good teacher and thank you for clarifying. Now, I can explain =WEEKDAY(0) to other people in **absolute details**. Epinn wrote: =MONTH(0) yields 1-Jan-1900...... Bob wrote: No, it yields 1. You just have it formatted as a date. Sorry, I skipped one step. I like programmers and/or accountants because they talk my language - exact and precise. Okay, I slipped occasionally. Is Norman Harker still around somewhere? Another MVP? After talking about 1900 for a few hours, I may have lost track of time. Okay, it is still 2006, I have just checked the clock on my computer. A while back, I had a post in another MS forum talking about "teleport" which was a feature I attempted to do using the MS software. I'll worry about WORKDAY() after I have got some rest. What does ATP stand for? Just looking at your formula, I am relieved although I haven't digested it yet. Do you want to see the three-line formula a reputable web site suggested? What do I do without you, Bob? Epinn "Bob Phillips" wrote in message ... "Epinn" wrote in message ... Thank you all. This has been very educational. I have a few comments. If I key 9/9/2006 into A1, what formula do I use in A2 to get 38969. Please advise. =A1 and format as General. As we said the underlying value of a date is just the number of days since 1st Jan 1900, so it is already that number. You just format it to see it. If I key 9/9/2006 into A1, I think I can reference A1 directly in the above formula, instead of entering =A1 in A2 and then using A2 in the above formula. Correct The argument: 2/14/2008 is the equivalent of: 2 divided by 14 divided by 2008 which equals: 0.0000711439954467843........Weekday( 0 ) is actually 12/31/1899 which is a Saturday or weekday 7 when the return_type used is 1 or omitted. Don't think I want to agree with this. I key in =WEEKDAY(0) into a cell, I get 7-Jan-00. Don't know why and not sure if we are talking about the same thing. You may not want to, but Biff is right. 1st Jan 1900 was a Sunday, the 31st Dec 1899 was a saturday, which is day 7 to WEEKDAY. You get 7-Jan-00 because it is formatted that way, the underlying value is 7. =MONTH(0) yields 1-Jan-1900. In both cases, we never got back to 1899. No, it yields 1. You just have it formatted as a date. A month number is not a date, it is the ordinal value of the month within the year. =WEEKDAY(--"1899/12/31") gives an error #VALUE! which makes sense as the date system starts at 1/1/1900. It does, as Excel "knows" that is not a date in its view of the world, but you can fool it =WEEKDAY(--"1900/01/01"-1) returns 7. Again as Biff, this is another nuance of Excel. Talking about 1899 makes me feel very old but all this is very interesting. Please keep the date talk going. It would be nice if Norman Harker joined the discussion. He has made the study of dates a speciality. Next I have to analyze the formula for "last workday of the current month." This formual is three-line long and uses EOMONTH(). Looks tough. If it gets too confusing, I'll just use it without understanding it. There is a shorter formula but uses "holidays" as part of the syntax. (Holidays is not a function.) How about =WORKDAY(DATE(YEAR(TODAY()),MONTH(TODAY())+1,0),-1) or without the ATP function =DATE(YEAR(A1),MONTH(A1)+1,0)-(MAX(0,WEEKDAY(DATE(YEAR(A1),MONTH(A1)+1,0),2) -5)) Epinn "Bob Phillips" wrote in message ... |
#22
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WEEKDAY()
I know what you mean about the format. I have experienced that problem so
often that I added an edit field to one of my toolbars which shows the format of the activecell. I cannot tell you how often I have found that useful, the cell that I thought was a number turns out to be text. Unfortunately, Norman seems to have been offline for quite some time. He is an Excel MVP, and he specialises in Excel financial and date and time functions (and giving extremely long and detailed answers vbg). If he were around I am sure he wouldn't have written you an answer that would explain things far better than I have. ATP is the Analysis Toolpak, a Microsoft Excel addin that provides some extra functions, of which the WORKDAY function is but one. and yes, I would be interested in seeing your 3 line solution (and also knowing where it was recommended G) BTW, my first formula is wrong, it should be =WORKDAY(DATE(YEAR(A1),MONTH(A1)+1,1),-1) -- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... Bob, =A1 and format as General. As we said...... Thank you for being patient and putting up with me. I am very unfamiliar with dates, just starting. I did hear you - "......underlying value of a date is just the number of days since 1st Jan 1900...... when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559......" I registered the small pieces of info and I thought I understood. But when I tried to piece them together ...... Here's what has happened. I had a blank cell and I thought I saw the format as "general." Then I keyed in a date like 21/4/2008 into the cell and I saw the exact same thing as I had keyed in. ***I was under the impression that "general" was still the format***. I didn't recheck the format at that point. When I did, I noticed that it was changed from "general" to "date." This is why I don't know that "general" format can display the actual no. of days. So, this is what I have missed and you can tell how green I am. You may not want to, but Biff is right. 1st Jan 1900 was a Sunday, the 31st Dec 1899 was a saturday, which is day 7 to WEEKDAY. You get 7-Jan-00 because it is formatted that way, the underlying value is 7. When I read Biff's writeup, I found it very logical because I did agree that 1/1/1900 was a Sunday. But when I keyed in =WEEKDAY(0) ...... =WEEKDAY(--"1900/01/01"-1) returns 7. Ah, this is what I have missed from Biff's writeup and what I didn't do. Now, I am totally convinced. Bob, you are such a good teacher and thank you for clarifying. Now, I can explain =WEEKDAY(0) to other people in **absolute details**. Epinn wrote: =MONTH(0) yields 1-Jan-1900...... Bob wrote: No, it yields 1. You just have it formatted as a date. Sorry, I skipped one step. I like programmers and/or accountants because they talk my language - exact and precise. Okay, I slipped occasionally. Is Norman Harker still around somewhere? Another MVP? After talking about 1900 for a few hours, I may have lost track of time. Okay, it is still 2006, I have just checked the clock on my computer. A while back, I had a post in another MS forum talking about "teleport" which was a feature I attempted to do using the MS software. I'll worry about WORKDAY() after I have got some rest. What does ATP stand for? Just looking at your formula, I am relieved although I haven't digested it yet. Do you want to see the three-line formula a reputable web site suggested? What do I do without you, Bob? Epinn |
#23
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WEEKDAY()
Thanks RD,
That is a lot tidier than my Vlookup! With the amount of computing power that is available these days there is no real need to shorten processes (make it work no matter how long winded and that's good enough is all that it really requires), however, I still like to cut corners wherever I can. Old Habits...etc, etc. Many Thanks Martin |
#24
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WEEKDAY()
"MartinW" wrote in message ... With the amount of computing power that is available these days there is no real need to shorten processes (make it work no matter how long winded and that's good enough is all that it really requires), however, I still like to cut corners wherever I can. Old Habits...etc, etc. I think there is. It is very easy to bring a spreadsheet to its knees with poor design, coding, etc. Keep looking to cut those corners. |
#25
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WEEKDAY()
I was in no way suggesting that Norman would explain things far better than you did. I was just wondering if he is someone of our time. Yes, good point, you are precise and concise which is very important as I can get lost in long strolls.
Everyone, I am going to start a new thread on WORKDAY(). If you are interested to join in, please move over. Epinn "Bob Phillips" wrote in message ... I know what you mean about the format. I have experienced that problem so often that I added an edit field to one of my toolbars which shows the format of the activecell. I cannot tell you how often I have found that useful, the cell that I thought was a number turns out to be text. Unfortunately, Norman seems to have been offline for quite some time. He is an Excel MVP, and he specialises in Excel financial and date and time functions (and giving extremely long and detailed answers vbg). If he were around I am sure he wouldn't have written you an answer that would explain things far better than I have. ATP is the Analysis Toolpak, a Microsoft Excel addin that provides some extra functions, of which the WORKDAY function is but one. and yes, I would be interested in seeing your 3 line solution (and also knowing where it was recommended G) BTW, my first formula is wrong, it should be =WORKDAY(DATE(YEAR(A1),MONTH(A1)+1,1),-1) -- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... Bob, =A1 and format as General. As we said...... Thank you for being patient and putting up with me. I am very unfamiliar with dates, just starting. I did hear you - "......underlying value of a date is just the number of days since 1st Jan 1900...... when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559......" I registered the small pieces of info and I thought I understood. But when I tried to piece them together ...... Here's what has happened. I had a blank cell and I thought I saw the format as "general." Then I keyed in a date like 21/4/2008 into the cell and I saw the exact same thing as I had keyed in. ***I was under the impression that "general" was still the format***. I didn't recheck the format at that point. When I did, I noticed that it was changed from "general" to "date." This is why I don't know that "general" format can display the actual no. of days. So, this is what I have missed and you can tell how green I am. You may not want to, but Biff is right. 1st Jan 1900 was a Sunday, the 31st Dec 1899 was a saturday, which is day 7 to WEEKDAY. You get 7-Jan-00 because it is formatted that way, the underlying value is 7. When I read Biff's writeup, I found it very logical because I did agree that 1/1/1900 was a Sunday. But when I keyed in =WEEKDAY(0) ...... =WEEKDAY(--"1900/01/01"-1) returns 7. Ah, this is what I have missed from Biff's writeup and what I didn't do. Now, I am totally convinced. Bob, you are such a good teacher and thank you for clarifying. Now, I can explain =WEEKDAY(0) to other people in **absolute details**. Epinn wrote: =MONTH(0) yields 1-Jan-1900...... Bob wrote: No, it yields 1. You just have it formatted as a date. Sorry, I skipped one step. I like programmers and/or accountants because they talk my language - exact and precise. Okay, I slipped occasionally. Is Norman Harker still around somewhere? Another MVP? After talking about 1900 for a few hours, I may have lost track of time. Okay, it is still 2006, I have just checked the clock on my computer. A while back, I had a post in another MS forum talking about "teleport" which was a feature I attempted to do using the MS software. I'll worry about WORKDAY() after I have got some rest. What does ATP stand for? Just looking at your formula, I am relieved although I haven't digested it yet. Do you want to see the three-line formula a reputable web site suggested? What do I do without you, Bob? Epinn |
#26
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WEEKDAY()
You might not of been, but I certainly was vbg
-- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... I was in no way suggesting that Norman would explain things far better than you did. I was just wondering if he is someone of our time. Yes, good point, you are precise and concise which is very important as I can get lost in long strolls. Everyone, I am going to start a new thread on WORKDAY(). If you are interested to join in, please move over. Epinn "Bob Phillips" wrote in message ... I know what you mean about the format. I have experienced that problem so often that I added an edit field to one of my toolbars which shows the format of the activecell. I cannot tell you how often I have found that useful, the cell that I thought was a number turns out to be text. Unfortunately, Norman seems to have been offline for quite some time. He is an Excel MVP, and he specialises in Excel financial and date and time functions (and giving extremely long and detailed answers vbg). If he were around I am sure he wouldn't have written you an answer that would explain things far better than I have. ATP is the Analysis Toolpak, a Microsoft Excel addin that provides some extra functions, of which the WORKDAY function is but one. and yes, I would be interested in seeing your 3 line solution (and also knowing where it was recommended G) BTW, my first formula is wrong, it should be =WORKDAY(DATE(YEAR(A1),MONTH(A1)+1,1),-1) -- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... Bob, =A1 and format as General. As we said...... Thank you for being patient and putting up with me. I am very unfamiliar with dates, just starting. I did hear you - "......underlying value of a date is just the number of days since 1st Jan 1900...... when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559......" I registered the small pieces of info and I thought I understood. But when I tried to piece them together ...... Here's what has happened. I had a blank cell and I thought I saw the format as "general." Then I keyed in a date like 21/4/2008 into the cell and I saw the exact same thing as I had keyed in. ***I was under the impression that "general" was still the format***. I didn't recheck the format at that point. When I did, I noticed that it was changed from "general" to "date." This is why I don't know that "general" format can display the actual no. of days. So, this is what I have missed and you can tell how green I am. You may not want to, but Biff is right. 1st Jan 1900 was a Sunday, the 31st Dec 1899 was a saturday, which is day 7 to WEEKDAY. You get 7-Jan-00 because it is formatted that way, the underlying value is 7. When I read Biff's writeup, I found it very logical because I did agree that 1/1/1900 was a Sunday. But when I keyed in =WEEKDAY(0) ...... =WEEKDAY(--"1900/01/01"-1) returns 7. Ah, this is what I have missed from Biff's writeup and what I didn't do. Now, I am totally convinced. Bob, you are such a good teacher and thank you for clarifying. Now, I can explain =WEEKDAY(0) to other people in **absolute details**. Epinn wrote: =MONTH(0) yields 1-Jan-1900...... Bob wrote: No, it yields 1. You just have it formatted as a date. Sorry, I skipped one step. I like programmers and/or accountants because they talk my language - exact and precise. Okay, I slipped occasionally. Is Norman Harker still around somewhere? Another MVP? After talking about 1900 for a few hours, I may have lost track of time. Okay, it is still 2006, I have just checked the clock on my computer. A while back, I had a post in another MS forum talking about "teleport" which was a feature I attempted to do using the MS software. I'll worry about WORKDAY() after I have got some rest. What does ATP stand for? Just looking at your formula, I am relieved although I haven't digested it yet. Do you want to see the three-line formula a reputable web site suggested? What do I do without you, Bob? Epinn |
#27
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WEEKDAY()
I must agree with Bob.
No matter how much computing power you have available, it is *very* easy to bring the program to it's knees with *deficient* formulas/coding. What can seem to operate efficiently in a 100 X 100 worksheet, can STOP an entire machine if inserted in a 10,000 row database sheet. And think what *will* happen with the XL07 *million* row program! For example: A Vlookup() formula, with an additional Vlookup() function call inserted for error checking in a 40,000 X 150 database sheet can take 20 minutes to load and/or recalc, where replacing it with an Index() and Match() combo can reduce that to under 10 minutes. Mind you, I'm *not* advocating XL's use as a database, just showing comparisons. AND ... *don't* try this at home ... BUT ... =SUM($A$1:A1) If used to produce a running total, works beautifully for several hundred rows, *BUT* Just copying down 15,000 - 20,000 rows, can take more then 2 or 3 minutes. AND - deleting that column of formulas can take in excess of 30 - 45 minutes. SO, you should/must *always* be in the market for shorter, more efficient, and/or smarter solutions. -- Regards, RD --------------------------------------------------------------------------- Please keep all correspondence within the NewsGroup, so all may benefit ! --------------------------------------------------------------------------- "Bob Phillips" wrote in message ... "MartinW" wrote in message ... With the amount of computing power that is available these days there is no real need to shorten processes (make it work no matter how long winded and that's good enough is all that it really requires), however, I still like to cut corners wherever I can. Old Habits...etc, etc. I think there is. It is very easy to bring a spreadsheet to its knees with poor design, coding, etc. Keep looking to cut those corners. |
#28
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WEEKDAY()
Hi Bob and RD
I guess I've got a bit of tunnelvision there! You are right of course, however, where I work we really don't have to be concerned about these sort of issues as all our spreadsheets are very small. A 100 x 100 sheet would be fairly large to us. Our sheets handle some very complex equations but any data analysis and data storage is handled by a couple of database programs. Basically we use Excel like a very powerful programmable scientific calculator. Rather than looking for a smart solution that will encompass all possibilities. It is quite often simpler to break a calculation down to small workable components with the use of helper cells and put it all back together at the end. Due to the fact that we are only using a very small part of the program's capabilities we can take a lot of freedoms that would be unthinkable in other disciplines (as you both quite rightly pointed out.) The bottom line is it works for us very very well. I'm sure there are plenty of other users who use Excel with the same cavalier attitude as ourselves but collectively we would be a very small minority group. Kind Regards Martin |
#29
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WEEKDAY()
Biff,
Thank you for taking the time to explain things to me, another "perfectionist." Unfortunately, I am learning how to run before I can walk steadily. Bob is right and I am having an episode of "information overload" at this time. I am sure that I can appreciate your analysis even better in the future and I look forward to more. By the way, "anal" is good, and I don't feel like I am the only one being detailed. All good programmers have a sense of perfection. Cheers, Epinn "Biff" wrote in message ... When you enter it into a function, the function treats it as its argument, and says that it is invalid as it expects a number (the true underlying value). 21/4/2008 is not a number here, so it errors. Actually, the formula does not "error" but calculates properly. The argument: 2/14/2008 is the equivalent of: 2 divided by 14 divided by 2008 which equals: 0.0000711439954467843 Since WEEKDAY only works with integers Excel truncates the value to 0. Weekday( 0 ) is actually 12/31/1899 which is a Saturday or weekday 7 when the return_type used is 1 or omitted. This is another Excel nuance. The date serial system doesn't start until day 1 which is 1/1/1900 yet you can calculate a date to be 1/0/1900. Excel treats the 0th day of the month as the last day of the previous month. That's how we end up with 7 as the result of the Weekday function. Biff "Bob Phillips" wrote in message ... But the difference is that when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559, which it presents/formats as that date. When you enter it into a function, the function treats it as its argument, and says that it is invalid as it expects a number (the true underlying value). 21/4/2008 is not a number here, so it errors. If you want to enter the date into the WEEKDAY function, you have to force it into a number, either using another function such as you did with DATE, or coerce it directly, like =WEEKDAY(--"21/4/2008") or my preferred format of =WEEKDAY(--"2008-04-21") -- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... Regarding WEEKDAY(), I read that problems can occur if dates are entered as text. Based on this, it is understandable that =WEEKDAY(2/14/2008) returns a wrong result (7). This is because general format is same as text. If I enter =WEEKDAY(DATE(2008,2,14)), I get the correct result (5). Okay, so far. What I don't understand is the following. I click A1 and key in 2/14/2008, then in A2, I key in =WEEKDAY(A1). I also get the correct result (5). The way I enter 2/14/2008 to A1 is exactly the same as I enter 2/14/2008 *directly* to the formula. It amazes me that referencing A1 in WEEKDAY() gives me the correct answer whereas keying it in as part of the formula won't work. Comments welcome. Epinn |
#30
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WEEKDAY()
I better clarify for those who haven't read the other thread. "Anal" is a compliment by _ _ _ and I just carried it over. Hope using the word here hasn't offended anyone.
Epinn "Epinn" wrote in message ... Biff, Thank you for taking the time to explain things to me, another "perfectionist." Unfortunately, I am learning how to run before I can walk steadily. Bob is right and I am having an episode of "information overload" at this time. I am sure that I can appreciate your analysis even better in the future and I look forward to more. By the way, "anal" is good, and I don't feel like I am the only one being detailed. All good programmers have a sense of perfection. Cheers, Epinn "Biff" wrote in message ... When you enter it into a function, the function treats it as its argument, and says that it is invalid as it expects a number (the true underlying value). 21/4/2008 is not a number here, so it errors. Actually, the formula does not "error" but calculates properly. The argument: 2/14/2008 is the equivalent of: 2 divided by 14 divided by 2008 which equals: 0.0000711439954467843 Since WEEKDAY only works with integers Excel truncates the value to 0. Weekday( 0 ) is actually 12/31/1899 which is a Saturday or weekday 7 when the return_type used is 1 or omitted. This is another Excel nuance. The date serial system doesn't start until day 1 which is 1/1/1900 yet you can calculate a date to be 1/0/1900. Excel treats the 0th day of the month as the last day of the previous month. That's how we end up with 7 as the result of the Weekday function. Biff "Bob Phillips" wrote in message ... But the difference is that when you key 21/4/2008 into cell A1, Excel recognises it as a date and converts it to an underlying value of 39559, which it presents/formats as that date. When you enter it into a function, the function treats it as its argument, and says that it is invalid as it expects a number (the true underlying value). 21/4/2008 is not a number here, so it errors. If you want to enter the date into the WEEKDAY function, you have to force it into a number, either using another function such as you did with DATE, or coerce it directly, like =WEEKDAY(--"21/4/2008") or my preferred format of =WEEKDAY(--"2008-04-21") -- HTH Bob Phillips (replace somewhere in email address with gmail if mailing direct) "Epinn" wrote in message ... Regarding WEEKDAY(), I read that problems can occur if dates are entered as text. Based on this, it is understandable that =WEEKDAY(2/14/2008) returns a wrong result (7). This is because general format is same as text. If I enter =WEEKDAY(DATE(2008,2,14)), I get the correct result (5). Okay, so far. What I don't understand is the following. I click A1 and key in 2/14/2008, then in A2, I key in =WEEKDAY(A1). I also get the correct result (5). The way I enter 2/14/2008 to A1 is exactly the same as I enter 2/14/2008 *directly* to the formula. It amazes me that referencing A1 in WEEKDAY() gives me the correct answer whereas keying it in as part of the formula won't work. Comments welcome. Epinn |
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