 Hi there, welcome back to my YouTube channel. This is Daniel Rosalier. I want to do a video explaining how to use TCL, which is a programming language in order to denote the time in different applications in Ubuntu Linux and also in different Linux distros. Now where you'll see this used is in application such as G world clock. G world clock is a little multiple time zone type application used in here AlexDE there is a fancier world time zone application in genome, but I'm a big fan of AlexDE LightWaste desktop environments in general and this is fine for me. So as you can see I'm in the process of setting this up and I'm just adding a few different time zones here to my program and the next thing I did I wanted to change the way the time is presented so if you look under preferences the preferences here are again very minimalistic you've got your local default short form short form or there is a there is an option here for roll your own now it doesn't say exactly how to roll your own and you'll see this in a few different sort of applications in Ubuntu and you can see that I put in my own syntax I'm very kind of finicky about how I present the time in my display applet and this just means well you've seen it but what I've gone for is just our colon minute and then the date and then the month just in brackets after that and this is how it looks on my time zone list as you can see so how do you know what the syntax is so TCL have documented here on their website the commands essentially and you can see there is actually tons and tons of different options because this is a kind of very very basic programming that I guess is just used in tons of different programs so you can see for instance the abbreviated weekday is for example mun choose when that is a percentage sign a then you've got a percentage sign h with a capital is hour now just my maybe neurotic references is I'm always a fan of the 24 hour time system which Americans I believe called military time so for instance if I wanted to say it is if I want to present the time like this cork 13 24 Monday right if I was trying to denote this in some kind of a programming system so what I would do is do this string of text and now I'm looking for the hour in a 24 hour format that's going to be a percentage h then a colon and then I'm going to need the minute that's going to be a percent sign and then I need my bracket and then I want that abbreviated and let's say I want to have the day as well so you can say okay it's like the 24th of the month and that's like how you want to show your time right so abbreviated weekday name is lowercase percentage lowercase a then I'm going to have a comma and then I want let us see the day of the month is percent sign d and then wrap that up so I'm going to actually go for this not the not the not the cork aspect specifically but I'm just going to copy this in and see if it works so you can find this reference on the tcl website there are tons this is like the friendlier version of its man page there is a very very extensive one that goes through like look you know lots and lots lots and lots and lots of variables but you're unlikely to need that much detail you're probably just going to need something of this nature and even just within some of these there's already some pretty obscure ones the year according to the closest century the julian day of the year like these would not be very common ones that you'd want to be displaying in clients or guis so just to recap on that percentage side age percentage sign capital M yeah that looks pretty good to me so I'm going to try now to put this in to G world clock so I'm going to go back to the roll your own option this time I'm going for this I'm going for the syntax we just put in I'm going to click apply and did it work did it work did it work yep work nicely so you can see I have now Sydney 8 a.m. Sunday the third I happen to have done this just just on the top of the error so that is basically it look up the tcl time and date functions and that will allow you to configure your time and date options in different programs running in Linux and different operating systems as well