# DATE
day=int(input('day:'))
month=int(input('month:'))
year=int(input('year'))
a=int(input('hours'))
b=int(input('mins'))
c=int(input('secs'))
if month==1 or month==3 or month==5 or month==7 or month==8 or month==10 or month==12:
max_days=31
elif month==2 or month==4 or month==6 or month==11:
max_days=30
elif year%4==0 and year%100!=0 and year%400==0:
max_days=29 and month ==2
elif month==2:
max_days=28
if month<1 or month>12:
print('invalit month')
elif day<1 or day>max_days:
print('invalid date')
else:
print('dd/mm/yy:',day,'/',month,'/',year)
print('yesterday :',day-1,'/',month,'/',year)
print('tom0rrow :',day+1,'/',month,'/',year)
OUTPUT
day:3
month:1
year2003
dd/mm/yy: 3 / 1 / 2003
yesterday : 2 / 1 / 2003
tom0rrow : 4 / 1 / 2003 @PYTHON