Trouble making to sources of time compare properly.

I have two sources of some [h]:mm.


One of them is manually entered: for example 27:34.

The other is the result of a formula that divides X by 3.5. (where X is the [h]mm between two date/time entries that look like this):

4/1/15 06:00 and 4/2/15 09:34 = 27:34


I'm trying a simple =if(a = b, "", a-b) on them, but I can't get a response until the manual entry is moved to 27:36.

It feel like there are some rounding errors, which I see when carried out to 9 decimal places, but that's not helping me at the moment.

This is the first h:mm that is doing this to me. Other values, such as 5:00 or 10:30, are working just fine.



thoughts?

I rounded down the seconds.

Works well now, thanks.