Gregorian calendar year
1 common year = 365 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 common year = 365 (days/year) x 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) = 31536000 seconds.
1 leap year = 366 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 leap year = 366 (days/year) x 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) = 31622400 seconds.
Julian year
1 julian year = 365.25 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 julian year = 365.25 (days/year) x 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) = 31557600 seconds.
Sidereal year
1 sidereal year = 365.25636 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 sidereal year = 365.25636 (days/year) x 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) = 31558149,504 seconds.
Tropical year
1 tropical year = 365.242189 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
1 Tropical year = 365.242189 (days/year) x 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) = 31556925,1296 seconds.