644

Millennium: 1st millennium
Centuries:
Decades:
Years:
644 in various calendars
Gregorian calendar644
DCXLIV
Ab urbe condita1397
Armenian calendar93
ԹՎ ՂԳ
Assyrian calendar5394
Balinese saka calendar565–566
Bengali calendar51
Berber calendar1594
Buddhist calendar1188
Burmese calendar6
Byzantine calendar6152–6153
Chinese calendar癸卯年 (Water Rabbit)
3341 or 3134
    — to —
甲辰年 (Wood Dragon)
3342 or 3135
Coptic calendar360–361
Discordian calendar1810
Ethiopian calendar636–637
Hebrew calendar4404–4405
Hindu calendars
 - Vikram Samvat700–701
 - Shaka Samvat565–566
 - Kali Yuga3744–3745
Holocene calendar10644
Iranian calendar22–23
Islamic calendar23–24
Japanese calendarN/A
Javanese calendar535–536
Julian calendar644
DCXLIV
Korean calendar2977
Minguo calendar1268 before ROC
民前1268年
Nanakshahi calendar−824
Seleucid era955/956 AG
Thai solar calendar1186–1187
Tibetan calendar阴水兔年
(female Water-Rabbit)
770 or 389 or −383
    — to —
阳木龙年
(male Wood-Dragon)
771 or 390 or −382
King Oswine of Deira (644–651)

Year 644 (DCXLIV) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar. The denomination 644 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.