;getnextdaydate.pro takes an input year, month and day and determines the
;day and month of the next day. Caution: Does not increment year.
;This program does work for leap year.
;Use is as follows:
;         getnextdaydate,year,month,day
;Where
;        input  |  year = 2 or 4-digit year (integer)
;
;  input/output |  month and day = integers of month and day are input
;                                  Next day overwrites inputed day and month.
;
;Note: When day=0 the next day is day=1 but the month doesn't change.
;        This should be compatible with the way dayflux.pro and dayflux_wc.pro
;        function.  BWBerger 3/2/00
;
;Written into a procedure by BWBerger 7/29/99 based on code in
;combineddayflux.pro written by KDavis.

pro getnextdaydate,year,month,day

day=day+1

case month of

     1 :begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end 
         
     3 :begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end 

     5 :begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end   

     7 :begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end 

    8 : begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end 

    10 :begin
        if(day gt 31)then begin
           month = month + 1
           day = 1
        endif 
        end 

    12 :begin
        if(day gt 31)then begin
           year = year + 1
           month = 1
           day = 1
        endif
        end

     2 :begin
        if year/4. eq fix(year/4.) then begin ;year is leap year
           if(day gt 29)then begin
              month = month + 1
              day = 1
           endif 
        endif else begin ;year is not a leap year
           if(day gt 28)then begin
              month = month + 1
              day = 1
           endif 
        endelse
        end 

  else :begin
        if(day gt 30)then begin
        month = month + 1
        day = 1
        endif 
        end  
endcase

return
end