uou can subtract one date from another ... as dates are
storeed numerically...
if you subtract one date from another, you get the number of
days with time difference as a fraction.
Access stores date/times in a numeric format where the
integer portion of the number represents the date and the
decimal portion of the number represents time:
1/1/100 --> -657434
1/2/100 --> -657433
12/30/1899 --> 0
1/1/1950 --> 18264
1/1/2005 --> 38353
1/1/9999 --> 2958101
the time is a fraction of the day
12 noon is 0.5
6pm is 0.75
1/1/2005, 12 noon --> 38353.5
if you have a control with just a date and you want to make
sure it converts to a whole number (or it is stored in text
format), use
DateValue([control_or_fieldname])
likewise, if you have a time, you can force it to the
fractional part by
TimeValue([control_or_fieldname])
since dates are whole numbers and time are the fractions,
theoretically, you can also do arithmetic operations on them
that is why you can subtract one date from another and get
the number of days between the two
The DateDiff function can be used to specify what time
increment you want returned when you subtract dates
Likewise, there is a DateAdd function to add specific time
increments to a date
***
Dates, therefore, are stored as floating point numbers. This
makes them inaccurate for direct comparisons anyway -- the
best way to ensure you have only the the Whole part of the
number (the date), is to use the Integer portion of the
number (the date) only -- this, in essence, is what
DateValue does. In addition to showing the result in a date
format, it strips off the decimals.
Have an awesome day
Warm Regards,
Crystal
MVP Microsoft Access
remote programming and training
strive4peace2006 at yahoo.com
