SLA_CALYD
Calendar to Year, Day
-
ACTION:
- Gregorian calendar date to year and day in year, in a Julian calendar aligned to the
20th/21st century Gregorian calendar, with century default.
-
CALL:
CALL sla_CALYD (IY, IM, ID, NY, ND, J)
GIVEN:
IY,IM,ID | I | year, month, day in Gregorian calendar: year may
optionally omit the century |
|
RETURNED:
NY | I | year (re-aligned Julian calendar) |
|
ND | I | day in year (1 = January 1st) |
|
J | I | status: |
|
| | 0 = OK |
|
| | 1 = bad year (before
) |
|
| | 2 = bad month |
|
| | 3 = bad day |
|
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NOTES:
-
-
(1)
- This routine supports the century default feature. Acceptable years are:
- 00-49, interpreted as 2000 – 2049,
- 50-99, interpreted as 1950 – 1999, and
- other years after ,
interpreted literally.
Use sla_CLYD for years before 100AD.
-
(2)
- The purpose of sla_CALDJ is to support sla_EARTH, sla_MOON and sla_ECOR.
-
(3)
- Between 1900 March 1 and 2100 February 28 it returns answers which are consistent with
the ordinary Gregorian calendar. Outside this range there will be a discrepancy which
increases by one day for every non-leap century year.
-
(4)
- When an invalid year or month is supplied (status J = 1 or J = 2) the results are not
computed. When a day is supplied which is outside the conventional range (status J = 3)
the results are computed.