Returns a string containing a month name.
mode tells this function which calendar to
convert the Julian Day Count to, and what type of month names are
to be returned.
Calendar modes
Mode
Meaning
Values
0
Gregorian - abbreviated
Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
1
Gregorian
January, February, March, April, May, June, July, August, September, October, November, December
2
Julian - abbreviated
Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
3
Julian
January, February, March, April, May, June, July, August, September, October, November, December