Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Time

Avatar for Dirkjan Bussink Dirkjan Bussink
February 10, 2015
Programming
130
0

 Time

A talk about how to handle time and timezones. Given at Twente.rb

Avatar for Dirkjan Bussink

Dirkjan Bussink

February 10, 2015

More Decks by Dirkjan Bussink

See All by Dirkjan Bussink
Managing a widely distributed team
Avatar for Dirkjan Bussink dbussink
1
200
The tricky truth about parallel execution and modern hardware
Avatar for Dirkjan Bussink dbussink
0
380
The future of Ruby is faster
Avatar for Dirkjan Bussink dbussink
3
560
Security for dummies
Avatar for Dirkjan Bussink dbussink
1
190
The myth of dynamic language performance
Avatar for Dirkjan Bussink dbussink
3
490
Rubinius - Tales from the trenches @ Railsclub.ru 2012
Avatar for Dirkjan Bussink dbussink
2
230
Rubinius - Tales from the trenches @ Baruco 2012
Avatar for Dirkjan Bussink dbussink
1
290
Rubinius Eurucamp 2012 Workshop
Avatar for Dirkjan Bussink dbussink
2
140
Rubinius Euruko 2012 Lightning talk
Avatar for Dirkjan Bussink dbussink
2
260

Other Decks in Programming

See All in Programming
Surviving Black Friday: 329 billion requests with Falcon!
Avatar for Samuel Williams ioquatix
0
2.9k
いつか誰かが、と思っていた フロントエンド刷新5年間の実践知
Avatar for Kiichi Sugihara kiichisugihara
1
260
Kubernetesを使わない環境にもCloud Nativeなデプロイを実現する / Enabling Cloud Native deployments without the complexity of Kubernetes
Avatar for linyows linyows
3
370
GoogleCloudとterraform完全に理解した
Avatar for Terisuke terisuke
1
190
[RubyKaigi 2026] Require Hooks
Avatar for Vladimir Dementyev palkan
1
310
ハーネスエンジニアリングにどう向き合うか 〜ルールファイルを超えて開発プロセスを設計する〜 / How to approach harness engineering
Avatar for r-kagaya rkaga
28
19k
Kingdom of the Machine
Avatar for yui-knk yui_knk
2
1.5k
AI-DLC Deep Dive
Avatar for yuukiyo yuukiyo
9
5.7k
なぜあなたのコードには「コシ」がないのか？〜AI時代に問う、最後まで美味しい設計と戦略〜 #phpconkagawa / phpconkagawa2026
Avatar for shogogg shogogg
0
150
20260514 - build with ai 2026 - build LINE Bot with Gemini CLI
Avatar for LINE Developers Taiwan line_developers_tw
PRO
0
390
運転動画を検索可能にする〜Cosmos-Embed1とDatabricks Vector Searchで〜/cosmos-embed1-databricks-vector-search
Avatar for 開発室Graph studio_graph
1
680
AIと共に生きる技術選定 2026
Avatar for Sugar Sato sgash708
0
130

Featured

See All Featured
Stewardship and Sustainability of Urban and Community Forests
Avatar for Eric Wiseman pwiseman
0
200
VelocityConf: Rendering Performance Case Studies
Avatar for Addy Osmani addyosmani
333
25k
Visual Storytelling: How to be a Superhuman Communicator
Avatar for David Neal reverentgeek
2
530
The Curious Case for Waylosing
Avatar for Cassini Nazir cassininazir
0
340
What’s in a name? Adding method to the madness
Avatar for The Alliance productmarketing
PRO
24
4k
The Psychology of Web Performance [Beyond Tellerrand 2023]
Avatar for Tammy Everts tammyeverts
49
3.4k
We Analyzed 250 Million AI Search Results: Here's What I Found
Avatar for Josh Blyskal joshbly
1
1.3k
The #1 spot is gone: here's how to win anyway
Avatar for Tamara Novitovic tamaranovitovic
2
1k
RailsConf 2023
Avatar for Aaron Patterson tenderlove
30
1.4k
AI: The stuff that nobody shows you
Avatar for John Nunemaker jnunemaker
PRO
6
630
SEO for Brand Visibility & Recognition
Avatar for Aleyda Solis aleyda
0
4.5k
Avoiding the “Bad Training, Faster” Trap in the Age of AI
Avatar for Mike Taylor tmiket
0
140

Transcript

  1. Time Dirkjan Bussink! @dbussink

  2. Time is hard

  3. None
  4. None
  5. None
  6. None
  7. None

  8. Basics

  9. None

  10. Timezones

  11. http://momentjs.com/

  12. http://momentjs.com/

  13. Storing

  14. UTC

  15. Why?

  16. 2014-10-26 02:34

  17. A bit more! complicated

  18. Group! by date

  19. None

  20. Who’s date?

  21. http://pellepim.bitbucket.org/jstz/

  22. None
  23. None

  24. Calculations

  25. None

  26. Perspective

  27. None

  28. UTC loses data

  29. UTC + offset

  30. 2014-08-19 16:12:50 +0200

  31. Time as a feature

  32. Calendars

  33. None
  34. None

  35. DST

  36. amsterdam = ActiveSupport::TimeZone["Europe/Amsterdam"] time = amsterdam.parse("2014-08-19 17:15") => Tue, 19

    Aug 2014 17:15:00 CEST +02:00

  37. sydney = ActiveSupport::TimeZone[“Australia/Sydney"] ! time => Tue, 19 Aug 2014

    17:15:00 CEST +02:00 time.in_time_zone(sydney) => Wed, 20 Aug 2014 01:15:00 EST +10:00

  38. later = time + 6.months => Thu, 19 Feb 2015

    17:15:00 CET +01:00 ! later.in_time_zone(sydney) => Fri, 20 Feb 2015 03:15:00 EST +11:00

  39. Our recurring meeting! just moved 2 hours!

  40. UTC + offset! isn’t good enough

  41. Time & time zone Europe/Amsterdam Tue, 19 Aug 2014 17:15:00

    CEST +02:00

  42. Time tracking

  43. Check in & check out

  44. 125% 22:00 00:00 150% Break 150% 01:00 01:30 06:00

  45. DST

  46. 125% 150% Break 150% 01:30 02:00 02:59 02:00 03:00

  47. 9 hours from 22:00 until 06:00

  48. Very specific! storage format

  49. Day!! ! ! ! ! ! ! 2014-10-26! Start!! !

    ! ! ! ! 79200!! ! ! End!! ! ! ! ! ! ! 108000! Duration!! ! 32400

  50. Take away

  51. Start with UTC

  52. Be careful! with timezones

  53. Make conscious! decisions