My update query is very slow...need help!!

I wrote 7 update queries for updating the field startofweek and endofweek depending on the reportday, it takes more than 2 hrs to run all of them for 250000 records, do anyone knows how to run these 7 queries faster?

for all records with reportday is on SUNDAY
UPDATE mastertable SET mastertable.Startofweek = [REPORTDAY], mastertable.Endofweek = [REPORTDAY]+6
WHERE (((DatePart("w",[REPORTDAY]))=1));

for all records with reportday is on MONDAY
UPDATE mastertable SET mastertable.Startofweek = [REPORTDAY]-1, mastertable.Endofweek = [REPORTDAY]+5
WHERE (((DatePart("w",[REPORTDAY]))=2));
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for all records with reportday is on Saturday
UPDATE mastertable SET mastertable.Startofweek = [REPORTDAY]-6, mastertable.Endofweek = [REPORTDAY]
WHERE (((DatePart("w",[REPORTDAY]))=7));

Just a suggestion.

Make a table called weeks.
Week StartDate EndDate
1 1-1-2004 1-7-2004
2 1-8-2004 1-14-2004
3 1-15-2004 1-21-2004

etc..

Then run one query

UPDATE mastertable SET mastertable.Week = Weeks.Week
WHERE mastertable.[Report Day] Between Weeks.[StartDate] And Weeks.[EndDate]

If you have not already done so, index all of the fields
you will be searching in the table.

"Tasha" ¼¶¼g©ó¶l¥ó
...
Just a suggestion.

Make a table called weeks.
Week StartDate EndDate
1 1-1-2004 1-7-2004
2 1-8-2004 1-14-2004
3 1-15-2004 1-21-2004

etc..

Then run one query

UPDATE mastertable SET mastertable.Week = Weeks.Week
WHERE mastertable.[Report Day] Between Weeks.[StartDate] And
Weeks.[EndDate]