DTDateTimeStringsDifference

Returns the difference in days or milliseconds of the first date & time string to the second date & time string.

DTDateTimeStringsDifference PROTO lpszDateTimeString1:DWORD, lpszDateTimeString2:DWORD, DateFormat:DWORD

Parameters

lpszDateTimeString1 - Pointer to a buffer containing the first date & time string. The format of the date & time string is determined by the DateFormat parameter.
lpszDateTimeString2 - Pointer to a buffer containing the second date & time string. The format of the date & time string is determined by the DateFormat parameter.
DateFormat - Value indicating the date & time format used in the buffer pointed to by both the lpszDateTimeString1 parameter and the lpszDateTimeString2 parameter. The parameter can contain one of the following constants as listed in the DateTime Formats page and as defined in the DateTime.inc include file.

Returns

On return EAX contains the difference between the two dates in days as an integer, either positive or negative.

On return EDX contains the difference in time or 0, see notes below for details.

Notes

If both dates are the same date, then EAX will be 0. If both date & time strings contain time values and the DateFormat parameter specified also provides a time format, then EDX will contain the difference in time in milliseconds.

Example

.data
CurrentDateTime db DATETIME_STRING dup (0)
SomeOtherDateTime db "2008/03/21",0

.data?
DayDifference dd ?
MillisecDifference dd ?

.code
Invoke DTGetDateTime, Addr CurrentDateTime, CCYYMMDDHHMMSSMS
Invoke DTDateTimeStringsDifference, Addr CurrentDateTime, Addr SomeOtherDateTime, CCYYMMDDHHMMSSMS
mov DayDifference, eax ; save day difference to data variable
mov MillisecDifference, edx ; save millisec diff if days the same

.IF eax == 0
     ; No difference in dates
     ; So MillisecDifference can be used
.ELSE
     ; Day difference is - or +, do something else...
     ; MillisecDifference is 0 value
.ENDIF