Time transcripts of julianDay [00:00:00:000] We are going convert January 16, 2016 at [00:00:04:010] 9 hours 54 minutes and 31 seconds into a [00:00:08:010] Julian day. The Julian day is 16. [00:00:12:020] because we are in January, that's pretty easy. [00:00:16:030] In order to convert the time, we need to know how many seconds there are in each of these parts. [00:00:20:030] And then we are going to divide by the total number of seconds in a day. [00:00:24:030] So what we know is that there are 60 seconds in one minute. [00:00:28:040] There are 60 minutes [00:00:32:040] in an hour. [00:00:36:050] 24 hours in a day. Okay. [00:00:40:050] And that means if you multiply 60 by 60 by 24 [00:00:44:050] then you can find out that there are 86,400 seconds [00:00:48:060] in one day. I feel like I'm singing [00:00:52:060] that song from "Rent." Okay, here's what we do: [00:00:56:070] We start with 9 hours and we say, all right, 9 hours [00:01:00:070] is 9 x 3600 which is the number of seconds in one [00:01:04:070] hour. That is going to give us 32,400 seconds. [00:01:08:080] Then we need to convert the minutes. 54 minutes multiplied [00:01:12:080] that by 60 because there are 60 seconds in a minute. And we get [00:01:16:080] 3240 seconds. [00:01:20:080] And then the 31 seconds we don't have to convert because that's already in seconds. [00:01:24:090] And we are going to add up these numbers. [00:01:28:090] And we get this number. [00:01:32:100] 35,671 seconds. We are going to divide [00:01:36:100] that by 86,400 because that is the total number of seconds in a day. [00:01:40:100] So divide, by 86,400. [00:01:44:110] And we get 0.4 [00:01:48:110] 129. Let's do a little reality check because I like [00:01:52:120] to do that when I do math. Is it possible that about [00:01:56:120] nearly 10 in the morning we've gone through about 40% of a 24-hour day? [00:02:00:120] Yeah, that makes sense to me because noon would be 50% and we're not [00:02:04:130] quite at noon yet, so this looks good. Okay, the answer [00:02:08:130] here finally is that the actual day precisely is [00:02:12:140] 16.4219. That's how you'd express the Julian day [00:02:16:150] with decimals of this date up here.