Time less than - Why do I always get false outcome?

Greetings everybody,

I was wondering if you could help me with one problem.
I cannot for the life of me understand why I always get false out of this formula.

A1 = 00:50 (formatted as time)

I put the following formula in B1

B1 = IF(A1<TIME(01;10;0);YES;NO)

So I read this like, 00:50 < 01:10 - which is true. Why does excel always return "NO" (false outcome) ?

Many thanks in advance guys!
Hjorrip

What's the value in A1 if it's formatted as General?

I expect it includes a date.

Thanks guys.
I know what is causing this, but I'm not sure how to fix that (I did the easy way of explaining when I started the thread, turns out that my example was just fine, but not what i was actually doing)

So I'm calculating how much time I can spend, depending on what time I can start, and what time I must finish.

I have 4 cells

A1 = Time I start (Time formatted) = 23:30
B1 = Time I finish (Time formatted) = 00:30
C1 = Duration (time formatted). Difference between A1 and B1 is 1 hour. I dont want any value in C1 if B1 is empty. I had problems with the time calculation due to midnight overpass, so I entered the following formula: This is where my error must be: =IF(ISBLANK(B1);"";IFERROR((B1+24)-A1;B1-A1))

And lastly, I use the formula to say yes or no if the time is less than TIME(1;10;0) - even though A3 shows only 01:00, i still get a false value when its suppose to be positive.

D1 = =IF(C1<TIME(1;10;0);"YES";"NO")

Values:
A1 = 23:30
B1 = 00:30
C1 = =IF(ISBLANK(B1);"";IFERROR((B1+24)-A1;B1-A1)) - Shows 01:00 with this formula'
D1 = =IF(C1<TIME(1;10;0);"YES";"NO") - Shows NO, I want to see YES

Thanks in advanced,
Hjorrip

With that method
IFERROR((B1+1)-A1,B1-A1)

If the time does NOT span midnight (a1 is 5:00 b1 is 7:00)
It will result in a time greater than 24 hours
Because (B1+1)-A1 is NOT an error, therefor it does not go to the standard B1-A1 part.
So B1+1 = 7 hours + 24 hours
(7 hours + 24 hours)-5 hours = (31 hours) - 5 hours. = 26 hours = 1 day 2 hours

Here's a very simple and common method for dealing with subtraction of times that span midnight.

MOD(B1-A1,1)

So try
=IF(B1="","",MOD(B1-A1,1))