Source code for NEDAS.models.topaz.time_format

from datetime import datetime, timedelta, timezone



def diy(iyr):
    if ( (iyr%4 == 0 and 1901+iyr%400==0) or (iyr % 4 != 0 )):
       days=365
    else:
       days=366
    return days




def forday(yrflag,dtime):
    #  converts model day to "calendar" date (year,ordinal-day,hour).
    if (yrflag==0):
        #  360 days per model year, starting Jan 16
        iyear =  int((dtime+15.001)/360) + 1
        iday  =  (dtime+15.001) % 360. + 1
        ihour = ( ( dtime+15.001) % 360. + 1. - iday)*24.
    elif (yrflag==1):
        # 366 days per model year, starting Jan 16
        iyear =  int((dtime+15.001)/366.) + 1
        iday  =  ( dtime+15.001 ) % 366. + 1
        ihour =  ( ( dtime+15.001 ) % 366. + 1. - iday)*24.
    elif (yrflag==2):
        # 366 days per model year, starting Jan 01
        iyear =  int((dtime+ 0.001)/366.) + 1.
        iday  =  ( dtime+ 0.001 ) % 366. + 1.
        ihour = ( ( dtime+ 0.001 ) % 366. + 1. - iday)*24.
    elif (yrflag==3):
        # model day is calendar days since 01/01/1901
        iyr   = int((dtime-1.)/365.25)
        nleap = iyr/4
        dtim1 = 365.*iyr + nleap + 1.
        day   = dtime - dtim1 + 1.
        if (dtim1>dtime):
           iyr = iyr - 1
        elif (day>=367.):
           iyr = iyr + 1
        elif ( (day>=366.) and (iyr % 4 != 3) ):
           iyr = iyr + 1
        nleap = int(iyr/4)
        dtim1 = 365.*iyr + nleap + 1.
        iyear =  1901 + iyr
        iday  =  dtime - dtim1 + 1.001
        ihour = (dtime - dtim1 + 1.001 - iday)*24
    else:
        raise ValueError(f"unknown yrflag {yrflag}")
    return int(iyear), int(iday), int(ihour)




def dayfor(yrflag, iyear,iday,ihour):
    # converts "calendar" date (year,ordinal-day,hour) to model day
    if     (yrflag==0):
       # 360 days per model year, starting Jan 16
       dtime =  (iyear-1) * 360. +  iday  + ihour/24. - 16.
    elif (yrflag==1):
       # 366 days per model year, starting Jan 16
         dtime = (iyear-1) * 366. + iday  + ihour/24.- 16.
    elif (yrflag==2):
       # 366 days per model year, starting Jan 01
       dtime = (iyear-1) * 366. + iday   - ihour/24. - 1.
    elif (yrflag==3):
       #model day is calendar days since 01/01/1901
       iyr=iyear-1901
       dtime=0.
       for k in range (iyr):
          dtime=dtime+diy(k+1901)

       iday2=iday
       while (iday2+ihour/24.>0.):
          iyr=iyr+1
          diy2=diy(iyr+1901)

          if ((iday2+(ihour/24.))/diy2>=1.):
             dtime=dtime+diy2
          else:
             dtime=dtime+iday2+ihour/24.
          iday2=iday2-diy2
    else:
        raise ValueError(f"unknown yrflag {yrflag}")
    return dtime




def datetojul(t, refyear=1950, refmonth=1, refday=1):
    if t.tzinfo is None:
        t = t.replace(tzinfo=timezone.utc)
    ref_t = datetime(refyear, refmonth, refday, tzinfo=timezone.utc)
    jday = (t - ref_t) / timedelta(days=1)
    return jday




def jultodate(jday, refyear=1950, refmonth=1, refday=1):
    ref_t = datetime(refyear, refmonth, refday, tzinfo=timezone.utc)
    t = ref_t + jday * timedelta(days=1)
    return t