A Tale about Time - LaravelLive India 2018

Timezones, DST, human readable diffs, standardised formats, intervals, getting the last Tuesday of next month… Dealing with timestamps seems easy, but there’s a lot to it. It’s very easy to do it wrong. Learn how to do this properly and you’ll never be chasing weird time related bugs anymore!

Transcript

1. A Tale about Time @hannesvdvreken @laravellivein
2. Hi, my name is Hannes.
3. !
6. A Tale about Time
7. 2018-03-17T10:15:00+05:30
11. EST = UTC-05:00
12. UTC+05:45
13. UTC+05:30
14. Helsinki Sunrise: 9:24 - 3:54 Sunset: 15:13 - 22:50 Quito Sunrise: 6:08 - 6:12 Sunset: 18:16 - 18:19
16. EST/EDT - March 12 CET/CEST - March 24
17. '
18. (
19. )
20. Storing vs Expressing time
21. 6:00PM vs 18:00
23. 1521261900 >1970-01-01T00:00:00+00:00
24. 1521261900 >1970-01-01T00:00:00+00:00 <2038-01-19T03:14:07+00:00
25. RFC3339: 2018-03-17T10:15:00+05:30
26. RFC3339 extended: 2018-03-17T10:15:00.000+05:30
27. Sortable: 2018-03-17T05:45:00.000+00:00
28. Calendars
29. Weeks - 7 days
30. Months Lunar vs Tropical
31. Years Lunisolar vs Tropical
32. 2018AD 1500BC
33. Leap years
34. Leap years Leap seconds
35. Time in PHP
36. DateTimeInterface - DateTime (date, time, tz) - DateTimeImmutable
37. $date = $date->setTimezone(‘Asia/Kolkata');
38. $date = DateTimeImmutable::createFromMutable($mutable);
39. Change in PHP 7.1: microseconds
40. // Magic $date = new DateTimeImmutable(‘now’); $date = $date->modify(‘first day of next month’);
41. “now + 5 hours” “first day of next month” "first weekday” …
42. “2016-03-00” → “2016-02-29” “2018-06-31” → “2018-07-01” …
43. “69-12-31” → “2069-12-31” “70-01-01” → “1970-01-01” …
44. nesbot/carbon - Mutable cakephp/chronos - Immutable
45. interface Clock { public function now(): DateTimeImmutable }
46. The future
47. E=mc²
48. c ~ 299.000.000m/s
51. Wrapping up
52. Thanks for your time! @hannesvdvreken @laravellivein
53. Time for questions. @hannesvdvreken @laravellivein