Best practices for handling time zone conversions in a multi-time zone software application using Node.js

Question

In multi-time zone software applications where the server operates in UTC time and users register from different time zones, what are the recommended best practices for handling time zone conversions to ensure accurate representation of dates and times across various user locations?

Specifically, I'm interested in understanding the optimal approach for scenarios where a user registers from one time zone (e.g., Indian Standard Time, UTC+5:30) and later views their data from a different time zone (e.g., Eastern Time, UTC-4). How can time zone conversions be managed to prevent discrepancies in displayed dates and times?

I'm seeking factual explanations with citations or references to authoritative sources, such as official documentation, industry standards, or established best practices in software development. Responses should focus on concrete strategies and evidence-based recommendations for handling time zone conversions effectively in software applications, particularly those built using Node.js and mongo.

Answer 1

Yes, in MongoDB all times are stored as UTC time, this you cannot change. The client application is responsible to display the date in the user local time zone (and format). Libraries like moment.js support these function.

Note, when you store a date/time in MongoDB then the initial time zone information is lost. Either you store the input time zone in a separate field or the user time zone is determined by the application, for example the client environment settings.

See also How can I ensure consistent datetime handling for a reservation system across different timezones?