VB & VBA in a Nutshell: The Language

DateDiff Function

Named Arguments

Yes

Syntax

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

interval

Use: Required

Data Type: String

The units of time used to express the result of the difference between date1 and date2 (see the table Section 7.53.3).

date1

Use: Required

Data Type: Variant (Date)

The first date you want to use in the differential calculation.

date2

Use: Required

Data Type: Variant (Date)

The second date you want to use in the differential calculation.

firstdayofweek

Use: Optional

Data Type: Numeric constant

A numeric constant that defines the first day of the week. If not specified, Sunday is assumed (see the table Section 7.53.4).

firstweekofyear

Use: Optional

Data Type: Numeric constant

A numeric constant that defines the first week of the year. If not specified, the first week is assumed to be the week in which January 1 occurs (see the table Section 7.53.5).

Interval Settings

Setting	Description
yyyy	Year
q	Quarter
m	Month
y	Day of year
d	Day
w	Weekday
ww	Week
h	Hour
n	Minute
s	Second

First Day of Week Constants

Constant	Value	Description
vbUseSystem	0	Use the NLS API setting
vbSunday	1	Sunday (default)
vbMonday	2	Monday
vbTuesday	3	Tuesday
vbWednesday	4	Wednesday
vbThursday	5	Thursday
vbFriday	6	Friday
vbSaturday	7	Saturday

First Week of Year Constants

Constant	Value	Description
vbUseSystem	0	Use the NLS API setting.
vbFirstJan1	1	Start with the week in which January 1 occurs (default).
vbFirstFourDays	2	Start with the first ...