28 BC

Millennium:	1st millennium BC
Centuries:	2nd century BC 1st century BC 1st century
Decades:	40s BC 30s BC 20s BC 10s BC 0s BC
Years:	31 BC 30 BC 29 BC 28 BC 27 BC 26 BC 25 BC

28 BC in various calendars

Gregorian calendar	28 BC XXVIII BC
Ab urbe condita	726
Ancient Greek era	188th Olympiad (victor)¹
Assyrian calendar	4723
Balinese saka calendar	N/A
Bengali calendar	−620
Berber calendar	923
Buddhist calendar	517
Burmese calendar	−665
Byzantine calendar	5481–5482
Chinese calendar	壬辰年 (Water Dragon) 2670 or 2463     — to — 癸巳年 (Water Snake) 2671 or 2464
Coptic calendar	−311 – −310
Discordian calendar	1139
Ethiopian calendar	−35 – −34
Hebrew calendar	3733–3734
Hindu calendars
- Vikram Samvat	29–30
- Shaka Samvat	N/A
- Kali Yuga	3073–3074
Holocene calendar	9973
Iranian calendar	649 BP – 648 BP
Islamic calendar	669 BH – 668 BH
Javanese calendar	N/A
Julian calendar	28 BC XXVIII BC
Korean calendar	2306
Minguo calendar	1939 before ROC 民前1939年
Nanakshahi calendar	−1495
Seleucid era	284/285 AG
Thai solar calendar	515–516
Tibetan calendar	阳水龙年 (male Water-Dragon) 99 or −282 or −1054     — to — 阴水蛇年 (female Water-Snake) 100 or −281 or −1053

Year 28 BC was either a common year starting on Saturday, Sunday or Monday or a leap year starting on Saturday or Sunday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Saturday of the Proleptic Julian calendar. At the time, it was known as the Year of the First Consulship of Octavian and Agrippa (or, less frequently, year 726 Ab urbe condita). The denomination 28 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Events

By place

Roman Republic

• Gaius Julius Caesar Octavian becomes Roman Consul for the sixth time. His partner Marcus Vipsanius Agrippa becomes Consul for the second time.
• The Roman Senate grants Octavian Caesar imperium maius (supreme command) of the Roman armed forces (Around 28 legions).
• Augustus initiates a census of the Roman Republic for the first time since 69 BC.

By topic

Astronomy

• May 10 – The earliest dated record of a sunspot by Chinese astronomers.

Deaths

• Alexandra the Maccabee, Hasmonean princess (approximate date)
• Mariamne I, Hasmonean princess and wife Herod the Great (or 29 BC)