New Chapter: Timezones

content/books/things-i-learnt/_index.md

@@ -39,6 +39,7 @@ template = "section-contentless.html"
 		* [If Your Data Has a Schema, Use a Structure](use-structures)
 		* [Don't Mess With Things Outside Your Project](outside-project)
 		* [Resist The Temptation Of Easy](resist-easy)
+		* [Always Use Timezones With Your Dates](use-timezones)
 * Community/Teams
 	* [A Language Is Much More Than A Language](languages-are-more)
 	* [Understand And Stay Away From Cargo Cult](cargo-cult)

content/books/things-i-learnt/languages-are-more/index.md

@@ -39,4 +39,4 @@ surface of what the whole of a language encapsulates and if you ignore the
 other elements in it, you may find yourself with a cute language in a
 community that is always fighting and never going forward.
 
-{{ chapters(prev_chapter_link="/books/things-i-learnt/resist-easy", prev_chapter_title="Resist The Temptation Of Easy", next_chapter_link="/books/things-i-learnt/outside-project", next_chapter_title="Don't Mess With Things Outside Your Project") }}
+{{ chapters(prev_chapter_link="/books/things-i-learnt/use-timezones", prev_chapter_title="Always Use Timezones With Your Dates", next_chapter_link="/books/things-i-learnt/outside-project", next_chapter_title="Don't Mess With Things Outside Your Project") }}

content/books/things-i-learnt/resist-easy/index.md

@@ -28,4 +28,4 @@ These days, IDEs can autocomplete almost everything, from function names to
 even how to name your variables. But using the autocomplete is not always a
 good solution. Finding better names is.
 
-{{ chapters(prev_chapter_link="/books/things-i-learnt/outside-project", prev_chapter_title="Don't Mess With Things Outside Your Project", next_chapter_link="/books/things-i-learnt/languages-are-more", next_chapter_title="A Language Is Much More Than A Language") }}
+{{ chapters(prev_chapter_link="/books/things-i-learnt/outside-project", prev_chapter_title="Don't Mess With Things Outside Your Project", next_chapter_link="/books/things-i-learnt/use-timezones", next_chapter_title="Always Use Timezones With Your Dates") }}

content/books/things-i-learnt/use-timezones/index.md

@@ -0,0 +1,35 @@
++++
+title = "Things I Learnt The Hard Way - Always Use Timezones With Your Dates"
+date = 2019-07-01
+
+[taxonomies]
+tags = ["en-au", "books", "things i learnt", "dates", "timezones"]
++++
+
+No matter if the date you're receiving is in your local timezone and you'll
+display it in your timezone. Sooner or later, the fact that you ignored there
+was a timezone behind that date will hurt you.
+
+<!-- more -->
+
+(Note: Most of this post when I say "date" you can think of "date and time",
+although the date should also be timezone aware.)
+
+At some point of my professional life, ignoring timezones was easy: You just
+pick the date, throw in the database, then read it back and everybody was
+happy.
+
+But things are not like this anymore. People will access your site from far
+away locations, the source of the date may not be in the same timezone of your
+system, your system may be running in a completely different timezone of your
+dev machine (it's pretty common to run things in our machines in the local
+timezone but the production system will run in UTC), the display may be a
+complete different timezone than your production and dev machine and so on.
+
+So always carry the timezone with the data. Find modules/classes that support
+dates with timezones (a.k.a. make things _timezone aware_), capture the
+timezone as soon as possible and carry it around in all operations.
+Modules/classes that don't support timezones for dates/times should, as soon
+as possible, removed from the system.
+
+{{ chapters(prev_chapter_link="/books/things-i-learnt/use-timezones", prev_chapter_title="Always Use Timezones With Your Dates", next_chapter_link="/books/things-i-learnt/languages-are-more", next_chapter_title="A Language Is Much More Than A Language") }}