Here are the figures that I left out of other pages to stop it looking too complicated. For those of you who want to know the details - this is the place. To find out what the terms used here mean look for the relevant page on the Site Index page.
|How long is a year?||
A tropical year is 365.242199 days UT which is equal to|
365 days, 5 hours, 48 minutes and 45 seconds.
A sidereal year is 365.256366 days UT which is equal to
365 days, 6 hours, 9 minutes, and 9.5 seconds.
An anomalistic year is 365.259636 days UT which is equal to
365 days, 6 hours, 13 minutes, and 33 seconds.
| How far has the Gregorian calendar|
drifted since it was decreed in 1582?
|2 hours, 59 minutes, 12 seconds.|
|When will the Gregorian calendar be one whole day out?||The year 4909 AD.|
|How many lunar months are there in a year?||12.368267|
|How long is a lunar month?||Its average length is 29 days, 12 hours, 44 minutes, and 2.9 seconds, or 29.530589 days.|
|How long is a second?||The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. Well you wanted to know!|