《尚书·周书·召诰》
二月十六日以后，到第六天乙未日，成王早晨从镐京出发，到了丰邑。
惟二月既望，越六日乙未，王朝步自周，则至于丰。
After the sixteenth day of February, on the sixth day of the first month, King Cheng set off from Haojing in the morning and arrived at Fengyi.