# Board index » delphi » Date and time converted to a number

## Date and time converted to a number

Hi.
I need to convert a date and time to the corresponding number of days since
y1900.

Example:
------------------
var   DateAndTime : TDateTime;
NumberOfDays : real;
begin
DateAndTime := Now;
NumberOfDays := ConvertToNumberOfDays(DateAndTime);
end;
----------------------

My question: How should the function "ConvertToNumberOfDays" look like?????
Is there an easy way????

Regards Peter.

## Re:Date and time converted to a number

"Peter Lund Andersen" <i...@nork.auc.dk> schreef in bericht
news:a6dggk\$gpb\$1@sunsite.dk...

##### Quote
> Hi.
> I need to convert a date and time to the corresponding number of days
since
> y1900.

----
Unit

System

type TDateTime = type Double;

Description

Most VCL objects represent date and time values using the TDateTime type.
The integral part of a TDateTime value is the number of days that have
passed since 12/30/1899. The fractional part of a TDateTime value is
fraction of a 24 hour day that has elapsed.

Following are some examples of TDateTime values and their corresponding
dates and times:

0 12/30/1899 12:00 am
2.75 1/1/1900 6:00 pm
-1.25 12/29/1899 6:00 am
35065 1/1/1996 12:00 am
To find the fractional number of days between two dates, simply subtract the
two values, unless one of the TDateTime values is negative. Similarly, to
increment a date and time value by a certain fractional number of days, add
the fractional number to the date and time value if the TDateTime value is
positive.
When working with negative TDateTime values, computations must handle time
portion separately. The fractional part reflects the fraction of a 24-hour
day without regard to the sign of the TDateTime value. For example, 6:00 am
on 12/29/1899 is 1.25, not 1 + 0.25, which would be 0.75. There are no
TDateTime values between 1 and 0.
---

--
Regards,

Dirk Claessens
---------------------------------------------------------
http://users.pandora.be/dirk.claessens2
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---------------------------------------------------------

## Re:Date and time converted to a number

In article <a6dggk\$gp...@sunsite.dk>, "Peter Lund Andersen" <i...@nork.auc.dk>
writes:

##### Quote
>My question: How should the function "ConvertToNumberOfDays" look like?????
>Is there an easy way????

Yes ...

trunc(DateAndTime)

Alan Lloyd
alangll...@aol.com