East Asian Age Reckoning, Wikipedia
↑Back-calculated from Lan Xichen’s age during the Sunshot Campaign. See Sunshot Campaign.
Back-calculated from Mo Xuanyu’s and Wei Wuxian’s ages at Wei Wuxian’s death; see Downfall of Wei Wuxian.
Back-calculated from Nie Mingjue’s age in comparison to Nie Huaisang, and his age at his father’s death.
Back-calculated from Jin Guangyao’s age; see Sunshot Campaign.
Back-calculated from Wei Wuxian’s age at the Night-hunt on Phoenix Mountain. See Downfall of Wei Wuxian.
Back-calculated: if Xue Yang was 15 when he gained notoriety, to be younger than Xiao Xingchen, he must be still around 15. See 11 – 13 Years Prior to Present Day.
Average length of Human Pregnancy is ~10 months
Depends on how long the “several months” before Jiang Yanli and Jin Zixuan’s marriage were, and the timing of Jin Ling’s birth.
Original Chinese, Chapter 69
Depending on how long the “several months” before Jiang Yanli and Jin Zixuan’s marriage were, and the timing of Jin Ling’s birth, it could have since been 2 years at the Burial Mounds.
During their early investigation in Yueyang, Lan Wangji identifies this as 12 years prior to present. However, given Jin Ling’s age at Wei Wuxian’s return, and Chapter 118 identifying Xiao Xingchen as being present 13 years ago, it seems probable this was between 12 – 13 years prior to present, and closer to 13. See Second Life of Wei Wuxian.
Original Chinese, Chapter 106
Back-calculated from Song Lan’s return to the cultivation world after Jin Guangshan’s death; see 0 – 11 Years Prior to Present Day.
Although the prologue says that 13 years have passed since Wei Wuxian’s death, the fact that Jin Ling turned 15 within several days indicates it actually closer to 14 years.
Considering that Wei Wuxian and Lan Wangji promised “every day” and that Mo Xiang Tong Xiu said they were married before their second time, it seems reasonable that they got married ≤1 day later.