The default date system for windows, 1900 date system, does not support
negative time. Perhaps you can multiply your result by 24 and show it as an
integer or decimal

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Regards,
Tom Ogilvy

"GBH99" wrote in message
...
I am having trouble formatting a cell so that when the number of hours
someone has completed for work against what they should have worked can
show
as a negative value instead of #############################.