AD 1

Millennium:	1st millennium
Centuries:	1st century BC 1st century 2nd century
Decades:	10s BC 0s BC 0s 10s 20s
Years:	3 BC 2 BC 1 BC AD 1 AD 2 AD 3 AD 4

AD 1 in various calendars
Gregorian calendar	AD 1 I
Ab urbe condita	754
Assyrian calendar	4751
Bengali calendar	−592
Berber calendar	951
Buddhist calendar	545
Burmese calendar	−637
Byzantine calendar	5509–5510
Chinese calendar	庚申年 (Metal Monkey) 2697 or 2637 — to — 辛酉年 (Metal Rooster) 2698 or 2638
Coptic calendar	−283 – −282
Discordian calendar	1167
Ethiopian calendar	−7 – −6
Hebrew calendar	3761–3762
Hindu calendars
- Vikram Samvat	57–58
- Shaka Samvat	N/A
- Kali Yuga	3101–3102
Holocene calendar	10001
Iranian calendar	621 BP – 620 BP
Islamic calendar	640 BH – 639 BH
Javanese calendar	N/A
Julian calendar	AD 1 I
Korean calendar	2334
Minguo calendar	1911 before ROC 民前1911年
Nanakshahi calendar	−1467
Seleucid era	312/313 AG
Thai solar calendar	543–544
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AD 1 (I), 1 AD or 1 CE is the epoch year for the Anno Domini calendar era. It was a common year starting on Saturday or Sunday, a common year starting on Saturday by the proleptic Julian calendar, and a common year starting on Monday by the proleptic Gregorian calendar. In its time, year 1 was known as the Year of the Consulship of Caesar and Paullus, named after Roman consuls Gaius Caesar and Lucius Aemilius Paullus, and less frequently, as year 754 AUC (ab urbe condita) within the Roman Empire. The denomination "AD 1" for this year has been in consistent use since the mid-medieval period when the anno Domini (AD) calendar era became the prevalent method in Europe for naming years. It was the beginning of the Christian/Common era. The preceding year is 1 BC; there is no year 0 in this numbering scheme.

The Julian calendar, which replaced the Roman calendar in 45 BC, was the calendar used by Rome in AD 1. The Anno Domini dating system was devised in AD 525 by Dionysius Exiguus.