Julian Years & Gregorian Years

Initial Calculations

The Bully Mnemonic reminds us that there are approximately 31556928 seconds in a tropical year:

$1 T r o p i c a l Y e a r \approx 31556928 s e c$

$1 T r o p i c a l Y e a r \approx (10330 - 0.40) \times 3055 = 31556928 s e c$

There are 86400 seconds in a day:

$1 D a y = 24 h o u r s \times \frac{60 m i n u t e s}{1 h o u r} \times \frac{60 s e c o n d s}{1 m i n u t e} = 86400 s e c o n d s$

The number of seconds in a 365 day year is:

$365 D a y = 365 \times 86400 s e c o n d s = 31536000 s e c o n d s$

The number of seconds in a 366 day year is:

$366 D a y = 366 \times 86400 s e c o n d s = 31622400 s e c o n d s$