Working with dates in JavaScript requires understanding quirks and patterns. Here's a comprehensive guide.
Creating Dates#
Getters and Setters#
Date Arithmetic#
Formatting Dates#
Comparison#
Start/End of Periods#
Timezone Handling#
Working with UTC#
Common Utilities#
Validation#
Date Range Generation#
Best Practices#
Creating Dates:
✓ Use ISO 8601 format for strings
✓ Remember months are 0-indexed
✓ Be explicit about timezone
✓ Use Date.UTC for UTC dates
Manipulation:
✓ Always create new Date objects (immutability)
✓ Use setters carefully (they mutate)
✓ Handle month overflow correctly
✓ Test edge cases (DST, leap years)
Formatting:
✓ Use Intl.DateTimeFormat for localization
✓ Store dates in UTC
✓ Display in user's timezone
✓ Use ISO format for APIs
Comparison:
✓ Compare timestamps, not objects
✓ Normalize to same timezone
✓ Consider start/end of day
✓ Handle invalid dates
Conclusion#
JavaScript date handling requires attention to timezones, zero-indexed months, and mutability. Use native Date for simple cases, Intl for formatting, and consider libraries like date-fns for complex operations. Always store in UTC and display in local time.