| Millennium: | 1st millennium |
|---|---|
| Centuries: | 1st century BC – 1st century – 2nd century |
| Decades: | 0s BC 0s 10s – 20s – 30s 40s 50s |
| Years: | 25 26 27 – 28 – 29 30 31 |
| 28 by topic | |
| Politics | |
| State leaders – Sovereign states | |
| Birth and death categories | |
| Births – Deaths | |
| Establishment and disestablishment categories | |
| Establishments – Disestablishments | |
| Gregorian calendar | 28 XXVIII |
| Ab urbe condita | 781 |
| Armenian calendar | N/A |
| Bahá'í calendar | -1816 – -1815 |
| Bengali calendar | -565 |
| Berber calendar | 978 |
| Buddhist calendar | 572 |
| Burmese calendar | -610 |
| Byzantine calendar | 5536 – 5537 |
| Chinese calendar | 丁亥年十一月十五日 (2664/2724-11-15) — to —
戊子年十一月廿六日(2665/2725-11-26) |
| Coptic calendar | -256 – -255 |
| Ethiopian calendar | 20 – 21 |
| Hebrew calendar | 3788 – 3789 |
| Hindu calendars | |
| - Bikram Samwat | 84 – 85 |
| - Shaka Samvat | N/A |
| - Kali Yuga | 3129 – 3130 |
| Holocene calendar | 10028 |
| Iranian calendar | 594 BP – 593 BP |
| Islamic calendar | 612 BH – 611 BH |
| Japanese calendar | |
| Korean calendar | 2361 |
| Thai solar calendar | 571 |
Year 28 (XXVIII) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar.