What am I doing wrong??

[Penguin]

I have tried over and over to calculate the number of days between to dates and I keep coming up with a blank. My dates are lastchangedate and it could be a month ago and the current data. I want to assign the number of days to a variable.
Here's the code

FormatTime, ld, lastChangeDate, yyyyMMdd

MsgBox, % "There are " DateDiff(ld, A_Now)
DateDiff( startdate, enddate)
{
units := "d"
enddate -= startdate, %units%
return enddate
}

thanks in advance

[Exaskryz]

Don't format your date into the ld; you want the full YYYYMMDDHH24MISS timestamp when doing the date subtraction. As you didn't give a value for lastChangeDate, I can't explicitly test it, but I'm sure that's the (or a) problem.

[Penguin]

My lastchange date variable comes in as text like this 4/21/16

[Exaskryz]

Looks like you'll want this to convert your lastChangedate into a proper timestamp: https://autohotkey.com/board/topic/1876 ... dhh24miss/

Otherwise you can convert it yourself; parsing shouldn't be too tough with a limited (personal) use case.

Code: Select all

string:="4/21/16"
StringSplit, components, string, /
stamp:="20" SubStr("0" components3, -1) SubStr("0" components1, -1) SubStr("0" components2, -1) "000000" ; midnight of this day
MsgBox % stamp
return

You can pass stamp (or call it ld) into your function then.

[Flarebrass]

Code: Select all

lastChangeDate := 20160419
;FormatTime, ld, lastChangeDate, yyyyMMdd
ld := lastChangeDate
;MsgBox, The old date is %ld%.

FormatTime, now, A_Now, yyyyMMdd
MsgBox, % "There are " . DateDiff(ld, now) . " days."
DateDiff(startdate, enddate)
{
    return enddate-startdate
}
ExitApp

enddate -= startdate is a complete statement. What you have after it, , %units% is erroneous and doesn't have any meaning. Also, you format the lastChangeDate but not A_Now, so those are in two different formats when you do the subtraction.

If that code doesn't work, then try Ex's string split method to format the time correctly at the beginning of my script.

The other issue that the number of days difference will be entirely wrong if the months are different. You need to include a type of calendar into your math in the DateDiff() function, and that's too much for me to code right now. My guess is maybe about 100 more lines of code for complete leap-year accuracy in the subtraction.

[just me]

Code: Select all

LastChangeDate := "4/21/16"
TimeStamp := Format("20{3:02}{1:02}{2:02}", StrSplit(LastChangeDate, "/")*)
MsgBox, % "There are " DateDiff(TimeStamp, A_Now) " days."
Return
DateDiff(startdate, enddate)
{
units := "d"
enddate -= startdate, %units%
return enddate
}

[Exaskryz]

@FlareBrass, see EnvSub

[Flarebrass]

I thought EnvAdd/EnvSub had to be explicitly called to work with dates. I'll have to start using that syntax!

[Penguin]

Thanks everyone. I go it to work