#  Friday13Faster.py  Copyright (c) Kari Laitinen

#  http://www.naturalprogramming.com

#  2006-05-17  File created.
#  2014-01-21  This program uses ISODate.py
#  2022-12-27  Converted to Python 3.

#  A faster version of program Friday13.py. 
#  Instead of using the increment() method of class ISODate,
#  this program increments the ISODate 'manually' to the following
#  13th day of a month.

#  In most cases this program behaves in the same way as
#  the original Friday13.py.

from ISODate import ISODate

print( "\n This program can print you a list of 10 dates"      \
       "\n that are Fridays and 13th days of a month."         \
       "\n Please, type in a date from which you want"         \
       "\n the calculation to begin. Type in the date"  \
       "\n in form YYYY-MM-DD and use four digits for"   \
       "\n the year and two digits for days and months:  ", end="" )

given_date_as_string  =  input()

date_to_increment  =  ISODate( given_date_as_string )

date_to_increment  =  ISODate( date_to_increment.year(),
                               date_to_increment.month(),
                               13 )

number_of_friday13_dates_to_print  =  10

print( "\n It is a common belief that you may have"  \
       "\n bad luck on the following dates:" )

while  number_of_friday13_dates_to_print  >  0  :

   if  date_to_increment.index_for_day_of_week()  ==  4  :

      print( "\n    %s, %s"  %  ( date_to_increment,
             date_to_increment.get_day_of_week() ), end="" )

      number_of_friday13_dates_to_print  -=  1

   if  date_to_increment.month()  <  12  :

      date_to_increment  =  ISODate( date_to_increment.year(),
                                     date_to_increment.month() + 1,
                                     13 )
   else :

      date_to_increment  =  ISODate( date_to_increment.year() + 1,
                                     1,
                                     13 )

print( "" )