Dates & Time

Timestamps, UTC and time-zone traps.

Dates & Time is taught here in 2 lessons, running from Unix timestamps & UTC through to Time zones & UTC offsets. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.

TrackComputer Science Fundamentals
Lessons2
LevelBeginner
Reading timeabout 26 minutes
PrerequisitesHelpful, but not required: Data Formats

Lessons

  1. Unix timestamps & UTCWhy storing time as a single number avoids almost every timezone bug, and the 2038 problem you should know about.
  2. Time zones & UTC offsetsWhy 'UTC+8' lies, what IANA zone names are for, and how to avoid the classic off-by-one date bugs.

More in Computer Science Fundamentals

Algorithms Data Structures Computer Networks Operating Systems Character Encodings Hashing & Checksums Data Formats Regular Expressions

FAQ

How long does the Dates & Time course take?
It has 2 lessons, about 26 minutes of reading. Expect roughly twice that if you type out and run every example.
Do I need prior experience for Dates & Time?
Not strictly. It helps to have read Data Formats first, because some lessons build on it, but every lesson explains its own assumptions.
What should I read after Dates & Time?
Continue with Regular Expressions (13 lessons), the next course in Computer Science Fundamentals.

Last refreshed 2026-09-18.