| Hongguang | |
| C: | 弘光 |
| P: | Hóngguāng |
| W: | Hung-kuang |
| L: | "great light" |
Hongguang (28 January – 17 August 1645) was the era name of the Hongguang Emperor of the Southern Ming.
On 7 June 1644 (Chongzhen 17, 3rd day of the 5th month), Zhu Yousong was proclaimed "regent" (監國) in Nanjing and ascended the throne on 19 June (15th day of the 5th month), taking next year Hongguang 1 (弘光元年, "the first year of Hongguang"). On May 1645 (5th month), the Qing army conquered Nanjing, and Zhu Yousong was captured on 15 June (22nd day of the 5th month). On 18 August 1645 (27th day of the leap 6th month), the Longwu Emperor ascended to the throne and continued to use it. The following month, the era was changed to Longwu. On 24 August (4th day of the 7th month), Zhu Yihai, Prince of Lu, proclaimed himself "regent" and still using the Hongguang era name, and the following year, the era was changed to Jianguo Lu 1 (監國魯元年, "the first year of Jianguo Lu").
The Gānzhī of each month on the right side of the table was the first day of each month. "(Long)" means that the month has 30 days, and "(Short)" means that the month has 29 days. The numbers in the "leap month" table indicate the X leap month of that year, and the numbers below the first day of each month indicate the corresponding Western calendar date.