math formula does not give the same result as bash script [SOLVED]

[AlphaInc]

This should divide by 12, not 4.

d = ((367 * (month-2-12*a)) / 4)

The other differences are caused by Python doing floating point math and bash doing integer math. The first pass at fixing your equations I tried this:

a = ((month-14) // 12)
b = ((year+4900+a) // 100)
c = ((1461*(year+4800+a)) // 4)
d = ((367 * (month-2-12*a)) // 12)

This was a little off. a was -1 instead of 0. When doing integer division, // does floor division, not truncating. Use int() to truncate.

Second pass.

a = int((month-14) / 12)
b = int((year+4900+a) / 100)
c = int((1461*(year+4800+a)) / 4)
d = int((367 * (month-2-12*a)) / 12)

I see no reason for adding 1 to the day. This is my version of your converter. I hard coded date to match your example.

from datetime import datetime


now = datetime.strptime("3 4 2023", "%d %m %Y")
# Remove comment to convert current date
# now = datetime.now()
day = now.day
month = now.month
year = now.year
print(day, month, year)

a = int((month-14) / 12)
b = int((year+4900+a) / 100)
c = int((1461*(year+4800+a)) / 4)
d = int((367 * (month-2-12*a)) / 12)
print(a, b, c, d)

Output:
3 4 2023
0 69 2492100 61

Ahh thank you. Didn't thought of that. But it worked :)