"Gee" wrote:
Why has this worked for about 3 hours and then suddenly stopped??

Define "working".


=IF(AND(HI2401,HI2<402),"YES","NO")

It probably has nothing to do with time of day, unless the value in H12 is
derived from time of day (i.e. NOW()).

More likely, the value in H12 is not what it appears to be. For example, if
the value is 401.00001, it might be displayed as 401, so you might expect
"NO". But AND(401<H12,H12<402) returns TRUE, so you actual get "YES".

If that is not enough to help you, post again with details, namely the
formula and value in H12, formatted to 13 decimal places.


----- original message -----

"Gee" wrote in message
...
Why has this worked for about 3 hours and then suddenly stopped??

Excel 2007 is what I'm using

=IF(AND(HI2401,HI2<402),"YES","NO")

Thank you in advance for any help you can give me.