Julian
Returns the classic Julian number of a Date.
Function Julian ( d : Date ) : LongInt;
DaysBetween
Returns the number of days between two dates.
Function DaysBetween( d1, d2 : Date ) : LongInt;
Negative days are reported if d2 is earlier d1.
DateAfter
MDY
Formats a date to Month dd, 19yy format
Function MDY( d : Date ) : String ;
Example.  const d : date = ( Year: 1992; Month:11; day:28);
Begin Writeln( MDY( d ) ) End.
result:   November 28, 1992
DateFormat
DateToField
Converts a date to a Dbase Date Field String type.
Function DateToField( d : Date ) : String;
The Dbase Date Format is : 19yymmdd
Checks valid date. Nul string returned if fails.
FieldToDate
DateToFormat
Formats a Date to a string format for display.
Function DateToFormat( d : Date ) : Str8 ;
The format wanted is selected through SetDateFormat.
DateToField, FieldToDate, FormatToDate, FieldToFormat
SetDateFormat
Sets the default date format for conversion.
Procedure SetDateFormat( form : Byte ) ;
Any conversion the returns or involves formatted date is
affected by the current format. In Tbase unit, FieldData,
Replace are affected. SAY in Dbedit is also affected.
FormatToDate, FormatToField, FieldToFormat, DateToFormat
Converts a Dbase Date Format to a Pascal Date type.
Procedure FieldToDate( s : String; Var d : date );
DayofWeek
Returns the Day of week in number for the specified date
Function DayOfweek( d : Date ) : Word;
The returned number  is between 0 and 6 with 0 for Sunday.
NameOfWeek
Returns the name of week for the day.
Function NameOfWeek( d : date ) : Str10 ;
Sunday, Monday.. Etc
DayOfWeek
Returns the date after a certain days
Procedure DateAfter( Var D : Date; days : LongInt );
Negative days willadvance the date as usual
The previous date will be lost. Be careful.
Today
Returns the Date of the System Clock in Date type
Procedure Today ( Var d : day );
ValidDate
Checks for the validity of a date and returns TRUE if valid.
Function ValidDate( d : Date ) : Boolean ;
FormatToDate
Converts a formatted date to a Pascal date.
Procedure FormatToDate( form: String;Var d : Date);
Form is assumed to be a formatted date according to the
current Date format set through SetDateFormat.
DateToFormat, FormatToField
FieldToFormat
Converts a Dbase Date format to Display Date format
Function FieldToFormat( Fielddate : String) : String;
Returned format is affected by Current format set through
SetDateFormat.
FormatToField
Converts a Display Date Format to a Dbase Date Format.
Function FormatToDate( Form : String ) : String;
Form is a formatted Date String according to the current
DaysFromZero ( Internal )
Returns the number of days from a certain date.
Function DaysFromZero( d : Date ) : LongInt;
This is the serial day from the given date. This is 1721119
days Less than the classical Julian Date.