Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Time is a Social Construct
Search
Daniel Cousineau
August 14, 2019
Programming
1
560
Time is a Social Construct
Given at BrooklynJS, ManhattanJS, and JSConf 2019
https://www.youtube.com/watch?v=EUzPpXhFmG8
Daniel Cousineau
August 14, 2019
Tweet
Share
More Decks by Daniel Cousineau
See All by Daniel Cousineau
React @ Scale
dcousineau
0
170
Frontend Performance & You
dcousineau
0
290
Feature Flags & You
dcousineau
2
96
React+Redux @ Scale
dcousineau
1
330
Reframing The Problem - DCJS July 2016
dcousineau
0
130
YAFT
dcousineau
2
150
Queues and the beanstalkd
dcousineau
1
660
How Not Writing PHP Makes You Better At PHP
dcousineau
0
380
JavaScript for PHP Developers
dcousineau
4
700
Other Decks in Programming
See All in Programming
dynamic!
moro
9
4.3k
なぜGoのジェネリクスはこの形なのか? Featherweight Goが明かす設計の核心
ryotaros
7
970
2025年版 サーバーレス Web アプリケーションの作り方
hayatow
23
25k
10年もののAPIサーバーにおけるCI/CDの改善の奮闘
mbook
0
610
Go Conference 2025: Goで体感するMultipath TCP ― Go 1.24 時代の MPTCP Listener を理解する
takehaya
7
1.4k
大規模アプリにおけるXcode Previews実用化までの道のり
ikesyo
0
950
iOSDC.pdf
chronos2500
2
640
Repenser les filtres API Platform: une nouvelle syntaxe
vinceamstoutz
2
150
CSC509 Lecture 01
javiergs
PRO
1
430
株式会社 Sun terras カンパニーデック
sunterras
0
170
詳しくない分野でのVibe Codingで困ったことと学び/vibe-coding-in-unfamiliar-area
shibayu36
1
460
プログラマのための作曲入門
cheebow
0
510
Featured
See All Featured
KATA
mclloyd
32
14k
Building a Scalable Design System with Sketch
lauravandoore
462
33k
Build The Right Thing And Hit Your Dates
maggiecrowley
37
2.9k
No one is an island. Learnings from fostering a developers community.
thoeni
21
3.5k
The Power of CSS Pseudo Elements
geoffreycrofte
78
6k
Building Applications with DynamoDB
mza
96
6.6k
GraphQLとの向き合い方2022年版
quramy
49
14k
Context Engineering - Making Every Token Count
addyosmani
3
140
Writing Fast Ruby
sferik
629
62k
A Tale of Four Properties
chriscoyier
160
23k
Scaling GitHub
holman
463
140k
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
panda_program
114
20k
Transcript
@dcousineau TIME IS A SOCIAL CONSTRUCT
@dcousineau SOCIAL CONSTRUCTS ARE GARBAGE
@dcousineau TIME IS GARBAGE
@dcousineau @dcousineau IS GARBAGE he/him
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau @dcousineau
@dcousineau 12pm Aug 15th, 2019
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau 12pm Aug 15th, 2019 UTC-0400
@dcousineau
@dcousineau 2019-08-15T12:00:00-0400
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau
@dcousineau @dcousineau
@dcousineau
@dcousineau 2019-08-15T16:00:00Z
@dcousineau @dcousineau
@dcousineau @dcousineau
@dcousineau Daylight Savings Time @dcousineau
@dcousineau Sun, Mar 10 @ 2am to Sun, Nov 3
@ 2am
@dcousineau 2019-08-15T16:00:00Z 2019-11-04T16:00:00Z 12pm in New York 11am in New
York
@dcousineau
@dcousineau
@dcousineau Arizona is in the Mountain Timezone and does not
observe daylight savings time except in the Navajo Indian Nation.
@dcousineau
@dcousineau Standard DST
@dcousineau 2019-03-10T02:01:00-07:00 “Fun” Fact Quiz
@dcousineau 2019-03-10T02:01:00-07:00 “Fun” Fact Quiz
@dcousineau
@dcousineau @dcousineau
@dcousineau
@dcousineau @dcousineau
@dcousineau
@dcousineau @dcousineau
@dcousineau
@dcousineau
@dcousineau America/New_York EST America/Chicago CST America/Denver MST America/Phoenix MST …
@dcousineau America/Indiana/Indianapolis America/Indiana/Knox America/Indiana/Marengo America/Indiana/Petersburg America/Indiana/Tell_City America/Indiana/Vevay America/Indiana/Vincennes America/Indiana/Winamac
@dcousineau Maybe Wikipedia can help…
@dcousineau
@dcousineau
@dcousineau 1918–1961
@dcousineau 1961–1967
@dcousineau 1967–1977
@dcousineau 1977–1991
@dcousineau 1991–2006
@dcousineau 2006–March 2007
@dcousineau March 2007–November 2007
@dcousineau November 2007–Today
@dcousineau America/New_York: Dearborn & Ohio America/Chicago: Jasper, Lake, LaPorte, Newton,
Porter, Gibson, Posey, Spencer, Vanderburgh, & Warrick America/Kentucky/Louisville: Clark, Floyd, & Harrison Counties in Indiana NOT on America/Indiana/*
@dcousineau 2019-08-15T12:00:00-0400 America/New_York
@dcousineau
@dcousineau So… did we learn anything?
@dcousineau Treat time as if it is irreducibly complex.
@dcousineau Time is a question of where almost as much
as it’s when.
@dcousineau Treat UTC like it’s merely a synchronization and conversion
aid.
@dcousineau Always preserve presented offsets / timezones. Only clone &
convert into UTC if storage requires.
@dcousineau Use ISO-8601 in transit & let the browser handle
the rest. Treat it like a11y, give the browser / user control.
@dcousineau Be explicit about context with your user. If this
is confusing for you, it’s worse for them.
@dcousineau USE A LIBRARY! Especially for simple arithmetic. date-fns, moment.js,
Luxon
@dcousineau When all else fails, just move to Florida. ☀
@dcousineau fin.