VBScript DateDiff function

Definition and usage

The DateDiff function can return the number of time intervals between two dates.

The DateDiff function is used to calculate the difference between two date-time values, the calculation method is date2 - date1.

If comparing years, ignore the values below the month; if comparing months, ignore the values below the day, and so on.

Note:The firstdayofweek parameter affects the calculation using the interval symbols 'w' and 'ww'.

Syntax

DateDiff(interval,date1,date2[,firstdayofweek[,firstweekofyear]])
Parameter Description
interval

Required. The unit of time interval between date1 and date2 to be calculated.

The following values can be used:

  • yyyy - Year
  • q - Quarter
  • m - Month
  • y - Day of the year
  • d - Day
  • w - Day of the week
  • ww - Week
  • h - Hour
  • n - Minute
  • s - Second
date1,date2 Required. Date expression. Two dates to be used in the calculation.
firstdayofweek

Optional. Specifies the number of days in a week, that is, the day of the week.

The following values can be used:

  • 0 = vbUseSystemDayOfWeek - Use the NLS API settings for the regional language.
  • 1 = vbSunday - Sunday (default)
  • 2 = vbMonday - Monday
  • 3 = vbTuesday - Tuesday
  • 4 = vbWednesday - Wednesday
  • 5 = vbThursday - Thursday
  • 6 = vbFriday - Friday
  • 7 = vbSaturday - Saturday
firstweekofyear

Optional. Specifies the first week of the year.

The following values can be used:

  • 0 = vbUseSystem - Use the NLS API settings for the regional language.
  • 1 = vbFirstJan1 - From the week containing January 1st (default).
  • 2 = vbFirstFourDays - From the first week of the year that has at least four days in the New Year.
  • 3 = vbFirstFullWeek - Start af den første fulde uge i det nye år.

Eksempel

Eksempel 1

document.write(Date & "<br />")
document.write(DateDiff("m",Date,"12/31/2002") & "<br />")
document.write(DateDiff("d",Date,"12/31/2002") & "<br />")
document.write(DateDiff("n",Date,"12/31/2002"))

Uddrag:

1/14/2002
11
351
505440

Eksempel 2

Bemærk i nedenstående kode, at date1>date2:

document.write(Date & "<br />")
document.write(DateDiff("d","12/31/2002",Date))

Uddrag:

1/14/2002
-351

Eksempel 3

Hvor mange uger ( starter på mandag),
er tilbage mellem den nuværende dato og 10/10/2002
document.write(Date & "<br />")
document.write(DateDiff("w",Date,"10/10/2002",vbMonday))

Uddrag:

1/14/2002
38