How to Manage Dates and Timezone in Code and Data

1. Introduction

In a software application, it's almost certain that we have to deal with the date in one way or another. And it's always a problem when working on a multi-timezone application.

It's always important that there is consistency and smooth conversion of date information across all applications and services.

2. Rules for Managing Date Information

Here are some rules that you can apply to manage the date.

2.1 The date information must be stored in UTC format in the database.

2.2 Date should be managed in UTC format in code.

2.3 Backend services must return a UTC format of the date.

2.4 Frontend must convert the date from UTC to the client's local timezone.

2.5 Frontend must use a standard format of the date. Preferably ISO 8601.

2.6 When the front end sends a date to the backend, it must be in ISO 8601 format. This will make conversion easier in the backend back to UTC format.

2.7 Take advantage of available libraries that can do date manipulation. 

3. Available Date Libraries

3.1 Java

• Joda-Time (https://www.joda.org/joda-time)
• Java-8 Date/Time
• Commons Lang (https://commons.apache.org/proper/commons-lang)

3.2 Javascript

• Moment (https://momentjs.com)