Imposible to substract a date

[Diego]

Hi everyone.

I am completely stuck trying to substract a number of days (say, 280) to a date... And I really don´t know what can be the problem.

For example, if I use "envsub":

today = %A_Now%
envsub, today, 280, days
FormatTime, today, %today%, yyyy-MM-dd
MsgBox, %today%
return

I get this error message in the second line:
: ==> Parameter #2 invalid.
Specifically: 280

Funnily enough, the same thing works absolutely fine if I add it (using "envadd") instead of substracting it:

today = %A_Now%
envadd, today, 280, days
FormatTime, today, %today%, yyyy-MM-dd
MsgBox, %today%
return

I have also tried the normal way, justs using "-=", but I get exactly the same error message:

today = %A_Now%
today -= 280, days
FormatTime, today, %today%, yyyy-MM-dd
MsgBox, %today%

Again, it works perfectly fine with "+=":

today = %A_Now%
today += 280, days
FormatTime, today, %today%, yyyy-MM-dd
MsgBox, %today%

I had version AutoHotkey_1.1.25.02 and have unistalled it and installed instead the latest one, AutoHotkey_1.1.26.01, just in case, but I am getting exactly the same results.

I am using:
- Windows Vista Home Premium Service Pack 2
- 32 bits operating system.

I am completely at odds with this...
Any help or ideas about how to fix it will be more than wellcome.

Cheers.

[Masonjar13]

You were very close! You can't use EnvSub for most date values (see the last line of text for the TimeUnits parameter). Use +=, but simply make the value negative.

Code: Select all

today:=a_now
today+=-240,days
formatTime,todayF,today,yyyy-MM-dd
msgbox % todayF

[BoBo]

Luckily reading our favourite manual is free of charge so let's try it again ...

To add or subtract a certain number of seconds, minutes, hours, or days from a timestamp, use EnvAdd (subtraction is achieved by adding a negative number).

[Diego]

Thanks so much.
Problem solved .

Of course first thing I did was to read the manual... But I quitted once I read the value could be any integer.

[jeeswg]

The names are slightly misleading:
EnvAdd increases/decreases a date by n seconds(/minutes/hours/days).
EnvSub returns the difference between two dates in seconds(/minutes/hours/days).
In AHK v2, the names are a bit clearer: DateAdd and DateDiff.

Link:
Syntax for time calculations - AutoHotkey Community
https://autohotkey.com/boards/viewtopic.php?f=5&t=39684