Datediff question?

[lkr1219]

I have a field (lbstdate) where i enter date and time - ex 03/20/2009 10:00 AM
I then enter end date and time (lbeddate) - ex 03/20/2009 11:30 AM

With this Me.LbNomHour = DateDiff("h", [LbStDate], [LbEdDate]) I get 1.0 and i lost the half hour.

with this Me.LbNomHour = DateDiff("n", [LbStDate], [LbEdDate]) I get 90.0 which means i have the half hour.

What i want to see is 1.5

How do i make that happen??

Thanks in advance for any thoughts you might have.

[WendellB]

In that case I believe you will have to do Me.LbNomHour = (DateDiff("n",[LbStDate],[LbEdDate]))/60. As far as I know these functions only return integer values.

[lkr1219]

[quote name='WendellB' post='766466' date='20-Mar-2009 20:09']In that case I believe you will have to do Me.LbNomHour = (DateDiff("n",[LbStDate],[LbEdDate]))/60. As far as I know these functions only return integer values.[/quote]


thank you!!! works great!!

[johnhutchison]

An easier solution is to subtract the earlier date/time from the later, and multiply the result by 24.
Date and times are just stored as numbers, with the days represented as whole numbers and the times by the dec points.

[MarkLiquorman]

You have to understand how DateDiff works. Depending on the interval you want, DateDiff returns the # of boundaries you crossed between the 2 date/times you specify.

For example: The result of DateDiff("d", #1/1/09 23:00#, #1/1/09 23:59#) is 0.
But if the 2nd date/time is only 2 minutes later, that is DateDiff("d", #1/1/09 23:00#, #1/2/09 00:01#), the result is 1.

Notice there is only 61 minutes separating the last 2 date/times, but since a day boundary was crossed, the result is 1 day.

Similarly, the result of datediff("m",#1/01/09#,#1/31/09#) is 0! There are 30 days between the 2 dates, but NO month boundaries.

Remember, it is the # of boundaries crossed. This is why the result is always an integer, and why there is no "rounding".

[patt]

[quote name='MarkLiquorman' post='766562' date='22-Mar-2009 00:12']You have to understand how DateDiff works. Depending on the interval you want, DateDiff returns the # of boundaries you crossed between the 2 date/times you specify.

For example: The result of DateDiff("d", #1/1/09 23:00#, #1/1/09 23:59#) is 0.
But if the 2nd date/time is only 2 minutes later, that is DateDiff("d", #1/1/09 23:00#, #1/2/09 00:01#), the result is 1.

Notice there is only 61 minutes separating the last 2 date/times, but since a day boundary was crossed, the result is 1 day.

Similarly, the result of datediff("m",#1/01/09#,#1/31/09#) is 0! There are 30 days between the 2 dates, but NO month boundaries.

Remember, it is the # of boundaries crossed. This is why the result is always an integer, and why there is no "rounding".[/quote]
That's a great explanation, thank you.

That kind of explanation really helps when trying to work these things out.

Makes a lot of sense too regarding boundaries hence integer calculation.