SLA_CALDJ - Calendar Date to MJD   

ACTION:

Gregorian Calendar to Modified Julian Date, with century default.

CALL:

CALL sla_CALDJ (IY, IM, ID, DJM, J)

GIVEN:

IY,IM,ID year, month, day in Gregorian calendar

RETURNED:

$$0^{\rm h}$$ DJM

J I status: 0 = OK 1 = bad year (MJD not computed) 2 = bad month (MJD not computed) 3 = bad day (MJD computed)

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
• 100 upwards, interpreted literally.

For 1-100AD use the routine sla_CLDJ instead.

2.

For year nBC use IY = -(n-1).

3.

When an invalid year or month is supplied (status J = 1 or 2) the MJD is not computed. When an invalid day is supplied (status J = 3) the MJD is computed.