Microsoft Office Tutorials and References
In Depth Information
But what if you want to add a month to
datFirst
? Depending on the month, you would need
to add either 28, 30, or 31 days. The
DateAdd
procedure lets you add a variety of time incre
ments to a date or time through the use of an ingenious syntax
DateAdd("
interval
",
number
,
date
)
in which
interval
is the code (in quotes) of the time unit,
number
is the number of times to
increment the date or time by the
interval,
and
date
is the date or time to which you want to
add the time. Table 9-6 lists the available units and their corresponding codes.
Table 9-6.
Codes for Intervals Used in the
DateAdd
Function
Unit
Code
yyyy
Year
q
Quarter (three months)
m
Month
ww
Week
y
Day of year
d
Day
W
Weekday
h
Hour
n
Minute
s
Seconds
For example, if you wanted to use a message box to display the date nine weeks from today,
you would use the following function:
MsgBox (DateAdd("ww", 9, DATE))
You can also use negative values within the
DateAdd
function to move backward in time. For
example, the function to return the time eight hours ago (reckoning from the current time
on your computer clock) would be
DateAdd("h", -8, NOW)
Note
You can also use negative values in the
DateSerial
and
TimeSerial
functions,
described earlier, but the
DateAdd
function gives you more flexibility by letting you use
different time units.
The
DateDiff
function, as the name implies, lets you find the number of time units (that is,
months, years, minutes, and so on) between two dates or times. The syntax is similar to that
of the
DateAdd
function, but instead of using a base date and an increment to determine an
end date, the
DateDiff
function uses two dates to determine the difference in interval
between them.
