All the date functions in VB6

Does somebody know all the (Date) functions aviable in Vb6?

[HeSaidJoe]

Just look up Date Function on your msdn disk..it should list them in the index.

[BruceG]

There is a bunch of them, they are listed in a book I have at home (I'm at work right now). The ones that stand out off the top of my head are:
DateDiff, DateAdd, CDate, Date, Time, Now, Weekday, WeekdayName, Month, Day, Year.

The Format$ function of course provides a variety of ways to format a date.

[HeSaidJoe]

'have fun...

'just the basics..there are plenty more

Function:

Day  Function:                        CDate(expression)

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Type Function:  	Date Data Type
      

Date variables are stored as IEEE 64-bit (8-byte) floating-point 
numbers that represent dates ranging from 1 January 100 to 31 
December 9999 and times from 0:00:00 to 23:59:59. Any recognizable 
literal date values can be assigned to Date variables.Date literals 
must be enclosed within number signs (#), for example, 
#January 1, 1993# or #1 Jan 93#.

Date variables display dates according to the short date format 
recognized by your computer. Times display according to the time 
format (either 12-hour or 24-hour) recognized by your computer.

When othernumeric types are converted to Date, values to the 
left of the decimal represent date information while values to 
the right of the decimal represent time. Midnight is 0 and 
midday is 0.5. Negative whole numbers represent dates before 30 
December 1899.

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Month Function
      

Returns a Variant (Integer) specifying a whole number between 
1 and 12, inclusive, representing the month of the year.

Syntax

Month(date)

The required dateargument is anyVariant,numeric expression,
string expression, or any combination, that can represent a date. 
If date containsNull, Null is returned.

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Now Function
      

Returns a Variant (Date) specifying the current date and 
time according your computer's system date and time.

Syntax

Now

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Weekday Function
      

Returns a Variant (Integer) containing a whole number representing 
the day of the week.

Syntax

Weekday(date, [firstdayofweek])

The Weekday function syntax has thesenamed arguments:

Part Description 
date Required.Variant,numeric expression,string expression, or 
any combination, that can represent a date. If date containsNull, 
Null is returned. 
firstdayofweek Optional. Aconstant that specifies the first day 
of the week. If not specified, vbSunday is assumed. 


Settings

The firstdayofweek argument has these settings:

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 


Return Values

The Weekday function can return any of these values:

Constant Value Description 
vbSunday 1 Sunday 
vbMonday 2 Monday 
vbTuesday 3 Tuesday 
vbWednesday 4 Wednesday 
vbThursday 5 Thursday 
vbFriday 6 Friday 
vbSaturday 7 Saturday 

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Year Function
      

Returns a Variant (Integer) containing a whole number representing 
the year.

Syntax

Year(date)

The required dateargument is anyVariant,numeric expression,
string expression, or any combination, that can represent a date. 
If date containsNull, Null is returned.

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Format Function
      

Returns a Variant (String) containing anexpression formatted 
according to instructions contained in a format expression.

Syntax

Format(expression[, format[, firstdayofweek[, firstweekofyear]]])

The Format function syntax has these parts:

Part Description 
expression Required. Any valid expression. 
format Optional. A valid named or user-defined format expression. 
firstdayofweek Optional. Aconstant that specifies the first day 
of the week. 
firstweekofyear Optional. A constant that specifies the first week 
of the year. 


Settings

The firstdayofweekargument has these settings:

Constant Value Description 
vbUseSystem 0 Use 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 


The firstweekofyear argument has these settings:

Constant Value Description 
vbUseSystem 0 Use NLS API setting. 
vbFirstJan1 1 Start with week in which January 1 occurs (default). 
vbFirstFourDays 2 Start with the first week that has 
at least four days in the year. 
vbFirstFullWeek 3 Start with the first full week of the year. 


Remarks

To Format Do This 
Numbers Use predefined named numeric formats or create user-defined 
numeric formats. 
Dates and times Use predefined named date/time formats or create 
user-defined date/time formats. 
Date and time serial numbers Use date and time formats or numeric 
formats. 
Strings Create your own user-defined string formats. 


If you try to format a number without specifying format, Format 
provides functionality similar to the Str function, although it is 
internationally aware. However, positive numbers formatted as 
strings using Format don’t include a leading space reserved for 
the sign of the value; those converted using Str retain the leading 
space.

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Type Conversion

CDate(expression)

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DateAdd Function
      

Returns a Variant (Date) containing a date to which a specified 
time interval has been added.

Syntax

DateAdd(interval, number, date)

The DateAdd function syntax has thesenamed arguments:

Part Description 
interval Required.String expression that is the interval of time 
you want to add. 
number Required.Numeric expression that is the number of intervals 
you want to add. It can be positive (to get dates in the future) or 
negative (to get dates in the past). 
date Required. Variant (Date) or literal representing date to which 
the interval is added. 


Settings

The intervalargument has these 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 


Remarks

You can use the DateAdd function to add or subtract a specified time 
interval from a date. For example, you can use DateAdd to calculate 
a date 30 days from today or a time 45 minutes from now.

To add days to date, you can use Day of Year ("y"), Day ("d"), or 
Weekday ("w").

The DateAdd function won't return an invalid date. The following 

DateAdd("m", 1, "31-Jan-95")

In this case, DateAdd returns 28-Feb-95, not 31-Feb-95. If date 
is 31-Jan-96, it returns 29-Feb-96 because 1996 is a leap year.

If the calculated date would precede the year 100 (that is, you 
subtract more years than are in date), an error occurs.

If number isn't aLong value, it is rounded to the nearest whole 
number before being evaluated.

Note   The format of the return value for DateAdd is determined 
by Control Panel settings, not by the format that is passed in date 
argument.

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DateDiff Function
      

Returns a Variant (Long) specifying the number of time intervals 
between two specified dates.

Syntax

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

The DateDiff function syntax has thesenamed arguments:

Part Description 
interval Required.String expression that is the interval of time you 
use to calculate the difference between date1 and date2. 
date1, date2 Required; Variant (Date). Two dates you want to use in 
the calculation. 
firstdayofweek Optional. Aconstant that specifies the first day of 
the week. If not specified, Sunday is assumed. 
firstweekofyear Optional. A constant that specifies the first week of 
the year. If not specified, the first week is assumed to be the week 
in which January 1 occurs. 


Settings

The intervalargument has these 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 


The firstdayofweek argument has these settings:

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 

Constant Value Description 
vbUseSystem 0 Use the NLS API setting. 
vbFirstJan1 1 Start with week in which January 1 occurs (default). 
vbFirstFourDays 2 Start with the first week that has at least four 
days in the new year. 
vbFirstFullWeek 3 Start with first full week of the year. 


Remarks

You can use the DateDiff function to determine how many specified 
time intervals exist between two dates. For example, you might use 
DateDiff to calculate the number of days between two dates, or the 
number of weeks between today and the end of the year.

To calculate the number of days between date1 and date2, you can 
use either Day of year ("y") or Day ("d"). When interval is 
Weekday ("w"), DateDiff returns the number of weeks between the 
two dates. If date1 falls on a Monday, DateDiff counts the number 
of Mondays until date2. It counts date2 but not date1. If interval 
is Week ("ww"), however, the DateDiff function returns the number 
of calendar weeks between the two dates. It counts the number of 
Sundays between date1 and date2. DateDiff counts date2 if it falls 
on a Sunday; but it doesn't count date1, even if it does fall on a 
Sunday.

If date1 refers to a later point in time than date2, the DateDiff 
function returns a negative number.

The firstdayofweek argument affects calculations that use 
the "w" and "ww" interval symbols.

If date1 or date2 is adate literal, the specified year becomes 
a permanent part of that date. However, if date1 or date2 is 
enclosed in double quotation marks (" "), and you omit the year, 
the current year is inserted in your code each time the date1 
or date2 expression is evaluated. This makes it possible to 
write code that can be used in different years.

When comparing December 31 to January 1 of the immediately 
succeeding year, DateDiff for Year ("yyyy") returns 1 even 
though only a day has elapsed.

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DatePart Function
      

Returns a Variant (Integer) containing the specified part of a 
given date.

Syntax

DatePart(interval, date[,firstdayofweek[, firstweekofyear]])

The DatePart function syntax has thesenamed arguments:

Part Description 
interval Required.String expression that is the interval of time 
you want to return. 
date Required. Variant (Date) value that you want to evaluate. 
firstdayofweek Optional. Aconstant that specifies the first day 
of the week. If not specified, Sunday is assumed. 
firstweekofyear Optional. A constant that specifies the first week 
of the year. If not specified, the first week is assumed to be the 
week in which January 1 occurs. 


Settings

The intervalargument has these 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 


The firstdayofweek argument has these settings:

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 


The firstweekofyear argument has these settings:

Constant Value Description 
vbUseSystem 0 Use the NLS API setting. 
vbFirstJan1 1 Start with week in which January 1 occurs (default). 
vbFirstFourDays 2 Start with the first week that has at least 
four days in the new year. 
vbFirstFullWeek 3 Start with first full week of the year. 


Remarks

You can use the DatePart function to evaluate a date and return a 
specific interval of time. For example, you might use DatePart to 
calculate the day of the week or the current hour.

The firstdayofweek argument affects calculations that use 
the "w" and "ww" interval symbols.

If date is adate literal, the specified year becomes a permanent 
part of that date. However, if date is enclosed in double quotation 
marks (" "), and you omit the year, the current year is inserted in 
your code each time the date expression is evaluated. This makes 
it possible to write code that can be used in different years.

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DateSerial Function
      

Returns a Variant (Date) for a specified year, month, and day.

Syntax

DateSerial(year, month, day)

The DateSerial function syntax has thesenamed arguments:

Part Description 
year Required; Integer. Number between 100 and 9999, 
inclusive, or anumeric expression. 
month Required; Integer. Any numeric expression. 
day Required; Integer. Any numeric expression. 


Remarks

To specify a date, such as December 31, 1991, the range of 
numbers for each DateSerialargument should be in the accepted 
range for the unit; that is, 1–31 for days and 1–12 for months. 
However, you can also specify relative dates for each argument 
using any numeric expression that represents some number of days, 
months, or years before or after a certain date.

The following example uses numeric expressions instead of 
absolute date numbers. Here the DateSerial function returns 
a date that is the day before the first day (1 - 1), two months 
before August (8 - 2), 10 years before 1990 (1990 - 10); 
in other words, May 31, 1980.

DateSerial(1990 - 10, 8 - 2, 1 - 1)

For the year argument, values between 0 and 29, inclusive, 
are interpreted as the years 2000–2029. Values between 30 
and 99 are interpreted as the years 1930–1999. For all other 
year arguments, use a four-digit year (for example, 1800).

When any argument exceeds the accepted range for that argument, 
it increments to the next larger unit as appropriate. For example, 
if you specify 35 days, it is evaluated as one month and some number 
of days, depending on where in the year it is applied. If any 
single argument is outside the range -32,768 to 32,767, an error 
occurs. If the date specified by the three arguments falls 
outside the acceptable range of dates, an error occurs.

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DateValue Function
      

Returns a Variant (Date).

Syntax

DateValue(date)

The required dateargument is normally astring expression 
representing a date from January 1, 100 through December 31, 9999. 
However, date can also be anyexpression that can represent a date, 
a time, or both a date and time, in that range.

Remarks

If date is a string that includes only numbers separated by 
validdate separators, DateValue recognizes the order for month, 
day, and year according to the Short Date format you specified 
for your system. DateValue also recognizes unambiguous dates 
that contain month names, either in long or abbreviated form. 
For example, in addition to recognizing 12/30/1991 and 12/30/91, 
DateValue also recognizes December 30, 1991 and Dec 30, 1991.

If the year part of date is omitted, DateValue uses the current 
year from your computer's system date.

If the date argument includes time information, DateValue 
doesn't return it. However, if date includes invalid time 
information (such as "89:98"), an error occurs.

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