Do you want entries in both C4 AND T4 then use

=IF(AND(ISNUMBER($C$4),ISNUMBER($T$4)),HOUR(IF($T$ 40.5,$T$4-0.5,IF($T$41/2
4,$T$4+0.5,$T$4)))&TEXT(MINUTE($T$4),"00"),"")

if you want entries in either C4 OR T4 use

=IF(OR(ISNUMBER($C$4),ISNUMBER($T$4)),HOUR(IF($T$4 0.5,$T$4-0.5,IF($T$41/24
,$T$4+0.5,$T$4)))&TEXT(MINUTE($T$4),"00"),"")

--
Regards,

Peo Sjoblom

(No private emails please, for everyone's
benefit keep the discussion in the newsgroup/forum)



wrote in message
...
Hello from Steved
The formula below works,

=HOUR(IF($T$40.5,$T$4-0.5,IF($T$41/24,$T$4+0.5,$T$4)))
&TEXT(MINUTE($T$4),"00"))

but when I add IF(ISNUMBER($C$4),the cells go blank which
is what I require, however when I put in a value, it stays
blank. Is their another solution to blank the cell please
as there are over 900 cells which I need to have blank if
there is no value to go in. (It is showing 1200, until i
enter a value.)

=IF(ISNUMBER($C$4),HOUR(IF($T$40.5,$T$4-0.5,IF
($T$41/24,$T$4+0.5,$T$4)))&TEXT(MINUTE($T$4),"00"))
Thankyou.