Zechariah 6:3

6:3 to the third white horses, and to the fourth spotted horses, all of them strong. ¹ 

Zechariah 8:19

8:19 “The Lord who rules over all says, ‘The fast of the fourth, fifth, seventh, and tenth ²  months will become joyful and happy, pleasant feasts for the house of Judah, so love truth and peace.’

[6:3]  ¹ tc For the MT reading אֲמֻצִּים (’amutsim, “strong”) Aquila and Syriac presuppose אֲדֻמִּים (’adummim, “red”), thus giving the red horse an assignment and eliminating the problem of a fifth, “spotted” horse. The fourth would be a mottled red horse according to this view. There is, however, no manuscript support for this interpretation.

[8:19]  ² sn The fasts of the fifth and seventh months, mentioned previously (7:5), are listed here along with the observances of the fourth and tenth months. The latter commemorated the siege of Jerusalem by the Babylonians on January 15, 588 b.c. (2 Kgs 25:1), and the former the breach of the city walls on or about July 18, 586 b.c. (Jer 39:2-5).