Time Difference in VBA Macro

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John Schneider - 03 Mar 2008 22:55 GMT

I'm trying to write a VBA macro to take the difference between two times
input by the user, calculate the difference, and put that value in the cell.

The first input box prompts for the start time (i.e. 9:00AM) and the second
prompts for the end time (i.e. 5:30PM). I've searched through this newsgroup
and done Google searches, but something just isn't sinking in. I need the
value to come out as a decimal value. With the 9:00 - 5:30 example, the cell
should show 8.5, but I keep getting -0.15. No doubt I'm missing something
obvious!

Thanks,
John

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Bob Phillips - 03 Mar 2008 23:05 GMT

Post up the code so we can see what you are doing.

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---
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

> I'm trying to write a VBA macro to take the difference between two times
> input by the user, calculate the difference, and put that value in the
[quoted text clipped - 12 lines]
> Thanks,
> John

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John Schneider - 03 Mar 2008 23:26 GMT

Its definately a work in progress, but here's what I have so far:

Sub testjs()

Dim startTime As String
Dim endTime As String
Dim totHours As String

startTime = Application.InputBox("Enter Start Time", "Calculate Hours", , ,
, , , 1)
endTime = Application.InputBox("Enter End Time", "Calculate Hours", , , , ,
, 1)

totHours = CDate(endTime) - CDate(startTime)

ActiveCell.Value = totHours

End Sub

> Post up the code so we can see what you are doing.
>
[quoted text clipped - 14 lines]
> > Thanks,
> > John

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Billy Liddel - 04 Mar 2008 00:34 GMT

Sub testjs()

Dim startTime As Date
Dim endTime As Date
Dim totHours As Date

startTime = Application.InputBox("Enter Start Time", "Calculate Hours", , ,
, , , 1) * 24
endTime = Application.InputBox("Enter End Time", "Calculate Hours", , , , ,
, 1) * 24

totHours = endTime - startTime
ActiveCell.Value = totHours
ActiveCell.NumberFormat = "00.00"
End Sub

StartTime entered as 9:0
EndTime entered as 17:30

Is this OK?

> Its definately a work in progress, but here's what I have so far:
>
[quoted text clipped - 33 lines]
> > > Thanks,
> > > John

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John Schneider - 04 Mar 2008 18:16 GMT

Billy,

That works perfect, but I don't understand why the time input (i.e. 9:00)
has to be multiplied by 24.

Thanks again!!!

> Sub testjs()
>
[quoted text clipped - 54 lines]
> > > > Thanks,
> > > > John

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Billy Liddel - 05 Mar 2008 09:32 GMT

John

Excel calculates dates as numbers, normally counting from 1/1/1900. Time is
calculated as fractions of a day. so 9:00 is 9/24 of a day. Bear this in mind
when making any calculations with time.

Peter

> Billy,
>
[quoted text clipped - 61 lines]
> > > > > Thanks,
> > > > > John

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John Schneider - 05 Mar 2008 15:10 GMT

Great explanation, and thanks again for the help!!!!

> John
>
[quoted text clipped - 69 lines]
> > > > > > Thanks,
> > > > > > John

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John Schneider - 10 Mar 2008 22:54 GMT

One more thing I can't figure out. The user inputs a start time, end time,
and how long for lunch. Something is wrong with the way I'm trying to
calculate this. The start and end times are absolute times (i.e. 8:30 am and
5:30 pm), but I need the "how long for lunch" to be just the number of
minutes, i.e. 45, 60, etc. How do I get this to work?

Here's my code:

Dim startTime As Date
Dim endTime As Date
Dim Lunch As Date
Dim totHours As Date

startTime = Application.InputBox("Enter Start Time", "Calculate Hours", , ,
, , , 1)
endTime = Application.InputBox("Enter End Time", "Calculate Hours", , , , ,
, 1)
Lunch = Application.InputBox("How Long For Lunch?", "Calculate Hours", , , ,
, , 1)

totHours = ((endTime - startTime) * 24) - (Lunch * 24)

ActiveCell.Value = totHours
ActiveCell.NumberFormat = "#0.0"

> > John
> >
[quoted text clipped - 3 lines]
> >
> > Peter

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ward376 - 11 Mar 2008 01:04 GMT

Divide the number of minutes by 1440 (24*60) to get a time serial
equivalent to the number of minutes.

Cliff Edwards

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