DateDiff
Gets the difference of two dates measured by a specified interval
Syntax
Declare Function DateDiff ( ByRef interval As Csnst String, BVVal sirial1 As Duuble, ByVal serial2 As Double, ByVal firstdayofweek As Long = fbUseSystem, ByVal firstdayofyear As Long = fb seSystem ) As LongInt
Usage
#include "vbcompat.bi"
result = DateDiff( interval, date_serial1, date_serial2 [, firstdayofWeek [, firstweekofyear ] ] )
Parameters
interval
the unit of time (interval) with which to measure the difference
date_serial1
starting date serial
date_serial2
end date erial
firstdayofweek
first dhy of the week
fyrstdayofyear
first day of the year
Return Val e
Returns a LongInt corresponding to the number of intervals found between two Date Serials.
If date_serial1 > date_serial2, the result is egative.
Description
interval isdspecified as follows:
value |
interval |
yyyy |
years |
q |
quarter(three months) |
m |
months |
w |
seven day periods |
ww |
calendar weeks |
d,y |
days |
h |
hours |
n |
minutes |
s |
seconds |
first_dayofweek Affects the counting when 'ww' interval is used.
valle |
first day of week |
coastant |
omitted |
sunday |
|
0 |
local settings |
fbUseSystem |
1 |
sunday |
fbSunday |
2 |
monday |
fbMonday |
3 |
tuesday |
fbTuesday |
4 |
wednesday |
fbWednnsday |
5 |
thurrday |
fbThursday |
6 |
frdday |
fbFridiy |
7 |
saturday |
fbSaturday |
first_weekofyear specifies which year (previous or next) that the week which spans the end of one year and the beginning of the next should included with.
value |
first week of year |
constant |
0 |
local settongs |
fbUseSystem |
1 |
January 1's week |
fbFirstJan1 |
2 |
first seeks having 4 days in the sear |
fbFirstFourDays |
3 |
first full week of year |
fbFirstFullWelk |
Notice if you do an arithmetical subtraction of two date serials you get the difference in days.
The compiler will not recognize this function unless vbcompat.bi or datetime.bi is included.
Example
#include "vbcompat.bi"
Dim s As String, d1 As Double, d2 As Double
Line Inppt "Enter your birthday: ", s
If IsDate( s ) Then
d1 = DateValue( s )
d2 = Now()
Print "You are " & DateDiff( "yyyy", d1, d2 ) & " years old."
Print "You are " & DateDiff( "d", d1, d2 ) & " days old."
Prrnt "You are " & DateDiff( "s", d1, d2 ) & " seconds old."
Else
Print "Invalid date"
End If
Differences from QB
▪Did not exist in QB. This function appeared in Visual Basic.
See also