There are a few different ways to represent dates and times in Ruby. 0:00 The Ruby date class is used to represent dates in Ruby, and 0:05 it has no concept of time. 0:09 So for example, 0:12 you could represent the day that you were born using the date class. 0:14 But not a specific time of day. 0:17 Let's go ahead and take a look at how the date class works now using WorkSpaces. 0:20 Okay, now we're going to take a look at the date library 0:26 as part of the Standard Library. 0:29 Now you'll notice that there are three different classes in use here, 0:31 Date, DateTime, and Time. 0:35 In this video we're just going to be concentrating on the Date class. 0:37 Now we're gonna use the Date class, unsurprisingly, 0:43 when we're working with dates. 0:46 And this is gonna be without a time component, 0:48 just to represent a certain date that you would like to in your program. 0:50 Now here are all of the different methods that are supported by the Date class. 0:55 Now we're just going to take a look at a few of these, but let's go ahead and 1:01 get right into a workspace. 1:06 So here I am in a workspace, I'm gonna launch irb. 1:08 Now, the first thing that we need to do since we're working with something from 1:14 the standard library is require it. 1:16 So we require date, and now we have this date class that we can work with. 1:19 If we were to just instantiate a date and called date.new, let's see what happens. 1:25 We get this new date, and the year is -4712, 1:31 on January 1st. 1:38 Now, we can also pass arguments to Date.new if we want to, 1:42 and that's done in the year month day format. 1:46 So we could do date.new, 2015, and then we'll say we want January 1st. 1:50 And now we get a new date object that has been instantiated to 2015-01-01. 1:58 If we go back to the documentation and 2:05 check out new, we can see the arguments that are supported. 2:09 By default the year starts out at -4712 and 2:15 the month is January and the day is the 1st of the month. 2:21 So we can play around with that and create dates pretty much anytime we want to. 2:26 2014, 7, 4, and that will create a date in the past. 2:31 Now, creating dates is one thing. 2:38 It's also useful to parse dates. 2:41 There's a method called parse that we can use that will take a string and 2:44 return a date object. 2:49 And if we look at parse, it says that parse is the given representation of 2:55 a date and time and creates just a date object. 2:58 So if we go back to our workspace and say Date.parse("July 4th, 3:01 2014"), we get back a date object that's 3:08 exactly what we would expect, July 4th, 2014. 3:12 And you'll notice if we use Date.parse, 3:23 we put in month, day, year, 3:28 and it parsed it out as year, month, day. 3:31 So that's something to keep in mind when you're using parse. 3:36 So here's another example. 3:40 If we wanted to do Date.parse("March 1st, 2015"), that works. 3:43 But if we wanted to pull out something like just the year, and say, 3:49 it's 2015 everyone, it will say that that's an invalid date. 3:54 Now, fortunately the Date class gives us another method that we can use 4:00 to parse more complicated dates. 4:04 So for example, using what we had just a minute ago, 4:08 if we wanted to parse out a different string, we can use the strptime method. 4:12 So where Date.parse didn't give us what we 4:18 were expecting, with 07/04/2014, that gave us something we weren't expecting. 4:23 We could use this strptime method. 4:29 We pass in the string as the first argument. 4:34 And then the format string is the second argument. 4:36 And we get back exactly what we were expecting. 4:43 And we're not limited to exactly this kind of format. 4:45 For example, we could do that other one where we tried 4:49 to parse "It's 2015, everyone!". 4:54 Invalid date, but if we tell this string that we're just looking for the year. 4:58 And then if we actually spell that correctly and take out the exclamation 5:19 point, this functions exactly as we would expect it to. 5:23 Let me clear my screen here and show you a couple other methods. 5:27 If you want to get today's date, we can call the method Date.today, 5:30 and as of the date of this recording, that is correct. 5:34 What's nice about dates is that we can do addition and subtraction on them. 5:37 So if I instantiated a new date to be today's date, 5:43 I could add 1 to it and it would give me tomorrow's date. 5:48 Could also do date- 1, which would give me yesterday's date. 5:52 Sadly, this does not work with multiplication. 5:56 And we get undefined method star for the date. 5:59 Now instead of adding one day we could also add or subtract months 6:03 using two greater than symbols and the number one that will add a month 6:10 to the date and then two less than symbols will subtract a month from the date. 6:15 I'm going to clear my screen one more time and 6:19 one other thing that we can do is format date. 6:22 So if we say date.to_s gives it one format. 6:26 But, using the strftime method, we can pass in another format string. 6:30 And it will print it out, just a little bit differently. 6:40 The format string I'm using right now is the year with four characters, 6:43 the month, a comma, and the day. 6:49 Now we can flip that around if we want. 6:51 And it'll tell us the day in pretty much any order that we want to. 6:55 If you're curious about the different possible format strings, 6:59 check out the notes below the video and you can see where they're coming from. 7:02 Try setting and manipulating dates on your own now using WorkSpaces. 7:06