Conditional Formatting based on Current Time ?

[Aitch]

I'm using the NOW function to give the time in cell A1

I thought it would be easy to highlight the row which corresponds to the time, by EXACT matching A1 to the column B... but it's not working!

What's the best way to get this to work?

Thanks for your help!

 

[jjasmith4]

Ultimately NOW() is a floating-point number, and any quant will tell you, you shouldn't ever do exact comparisons with floating-point numbers, even with zero, because computers always have rounding errors. The general way to compare floating-point numbers is to subtract them and see if the absolute value of the difference is within a small tolerance.

So with numbers you would not use "=$A$1=B1" but instead "=ABS($A$1-B1)<0.00001" to determine equality to the fifth decimal place; with times you should use "=ABS($A$1-B1)<TIME(0,0,0.1)" to determine precision within a tenth of a second.


Note that I've used absolute addressing with $A$1, but not B1; this is so that when you copy formats downward, including conditional ones, $A$1 doesn't change, but B1 does.

 

[DanteAmor]

You can compare the text of both hours

=TEXT($A$1,"hh:mm")=TEXT(B3,"hh:mm")




For the time to update and move the highlight cell you can put the following code in the events of your sheet

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    Application.Volatile
    Calculate
    DoEvents
End Sub

Every time you select any cell the time in A1 will be updated

 

[jjasmith4]

Faster would be Range("A1").Calculate

 

[DanteAmor]

Faster would be Range("A1").Calculate

Or simply calculate but I wanted to ensure the change of the formula to update the conditional format

 

[DanteAmor]

Use this formula:

=TEXT($A$1,"hh:mm")=TEXT($B3,"hh:mm")



It is important that in $B3 only have & before B

Apply To:
=$1:$1048576

 

[Aitch]

Thank you for the replies guys!

 

[DanteAmor]

You're welcome