Date Functions
See The Julian and the Gregorian Calendars for historical and theoretical background to this subject.

The functions described here all declared in the header file L_DATE.H. This header file should be #included in any source module which uses a date function from this library.

General Explanatory Remarks


Brief Descriptions of the Functions
(with links to full descriptions and sample programs)

date_earlier() Reports if one date is earlier than another.
date_to_days_since_111() Returns days since 1901-01-01 for a particular date.
date_to_iso_date() Converts a Date structure to a date string in ISO format.
date_to_str() Converts a date to a character string with user-specified date format.
date_valid() Reports if a date is a valid date.

The documentation for the following functions is provided with a user license:

day_name() Returns "Sunday", etc.
day_of_week() Returns day-of-week for a particular date.
days_elapsed() Returns number of days elapsed from one date to another..
days_in_date_range() Returns number of days in a range of dates.
days_in_month() Returns number of days in a given month.
days_in_year() Returns number of days in a given year.
days_since_111_to_date() Returns date for number of days since 1901-01-01.
euro_date_to_jdn() Converts a date in either the Gregorian or the Julian Calendar to a Julian day number.
euro_day_of_week() Returns day-of-week for a given Julian day number.
fvf_euro_date_to_jdn() Converts a date in the Gregorian Calendar to a Julian day number.
fvf_jdn_to_euro_date() Converts a Julian day number to a date in the Gregorian calendar.
get_system_date() Fills in a Date structure with the system date.
is_euro_leap_year() Reports if a year is a leap year.
is_weekday() Reports if a date is a weekday.
iso_date_to_date() Fills in a Date structure from a date string in ISO format.
jdn_to_euro_date() Converts a Julian day number to a date in either the Gregorian or the Julian Calendar.
month_name() Returns "January", etc.
next_date() Gets the next date..
nth_day_of_wk() Finds the nth day-of-week on or after a given date.
previous_date() Gets the previous date.
rom_bios_date() Returns the ROM BIOS date.
set_date_format_default() Sets up the default date format.
set_language() Specifies language (currently English or German).
set_system_date() Sets the system date.
sltoa_commas() Converts a signed long int to a string using comma-separated thousands.
sltoa_intl() Converts a signed long int to a string using a specified thousands-separator
str_to_date() Fills in a Date structure from a date string.
weekday_jan_1st() The day of the week for January 1 of a given year in a given calendar.
weekdays_in_date_range() Returns the number of weekdays in a time period.
weekdays_in_month() Returns the number of weekdays in a given month.
weekdays_in_year() Returns the number of weekdays in a given year.
yeartoa() Converts a year (a signed long int) to a string using comma-separated thousands.
yeartoa_intl() Converts a year (a signed long int) to a string using a specified thousands-separator.



Email
Index
Home Page

Last modified: 1998-09-03