 | This template is used on approximately 3,200 pages and changes may be widely noticed. Test changes in the template's /sandbox or /testcases subpages, or in your own user subpage. Consider discussing changes on the talk page before implementing them. |
 | This template uses Lua: |
Template:Year category header is used on year categories that fit one of the following styles:
- Years: Category:2000
- Decades: Category:2000s
- Centuries: Category:21st century
- Millennia: Category:3rd millennium