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All Functions
CDate Function
Date Function
DateAdd Function
DateDiff Function
DatePart Function
DateSerial Function
DateValue Function
Now Function
Time Function
FUNCTION: DateDiff( )
Implemented in version 2.0
DateDiff
(Interval, Date1, Date2,
FirstDayofWeek, FirstWeekofYear
)
The
DateDiff
function calculates the amount of time between two different dates.
There are three mandatory arguments.
Interval
The
Interval
argument defines the the type of time interval you wish to use to calculate the time difference.
Only the following settings can be used. You must place the setting inside a pair of double quotes.
SETTING
DESCRIPTION
YYYY
Year
Q
Quarter
M
Month
Y
Day Of Year
D
Day
W
WeekDay
WW
Week Of Year
H
Hour
N
Minute
S
Second
Date1
The
Date1
argument is the first date.
Date2
The
Date2
argument is the second date.
Code:
<%=DateDiff("d", Date, "1/1/2000") %>
Output:
291
The order of the two dates determines if the difference is represented as a positive or negative value.
Code:
<% olddate = #6/26/43# %>
<% nowdate = Now %>
<% =DateDiff("s", nowdate, olddate) %>
Output:
-3130748108
There are two optional arguments.
FirstDayofWeek
The
FirstDayofWeek
argument must only use the constants or values defined below in the Date And Time CONSTANTS.
CONSTANT
VALUE
DESCRIPTION
VBSunday
1
Sunday
VBMonday
2
Monday
VBTuesday
3
Tuesday
VBWednesday
4
Wednesday
VBThursday
5
Thursday
VBFriday
6
Friday
VBSaturday
7
Saturday
VBFirstJan1
1
Week of January 1
VBFirstFourDays
2
First week of the year that has at least four days
VBFirstFullWeek
3
First full week of the year
VBUseSystem
0
Use the date format of the computer's regionsl settings
VBUseSystemDayOfWeek
0
Use the first full day of the week as defined by the system settings
In this example, Tuesday is defined to be the first day of the week. The output is how many weeks, which are now defined to start on Tuesday, are left between the current date and 1/1/2001.
Code:
<% =DateDiff("w", Date, "1/1/2001", 3) %>
Output:
93
Code:
<% =DateDiff("w", Date, "1/1/2001", VBTUESDAY) %>
Output:
93
FirstWeekofYear
The
FirstWeekofYear
argument must only use the constants or values defined in the Date And Time CONSTANTS which are listed above.
Code:
<% =DateDiff("ww", Date, "1/1/2001", 1, VBFIRSTFOURDAYS)%>
Output:
94
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