Another commonality across many languages is naming days of the week after celestial bodies: Sunday Sun Sōlis Hēlíou 日曜日 Monday Moon Lūnae Selḗnēs 月曜日 Tuesday Mars Mārtis Áreōs 火曜日 Wednesday Mercury Mercuriī Hermoû 水曜日 Thursday Jupiter Iovis Diós 木曜日 Friday Venus Veneris Aphrodítēs 金曜日 Saturday Saturn Sāturnī Krónou 土曜日 https://en.wikipedia.org/wiki/Names_of_the_days_of_the_week
In fact, one could argue that in its place, naming after the days of a fortnight is more intuitive : since it coincides with the phases of the moon. Indeed, the Sanskrit way of naming days (not used popularly except in religious and astrological settings) uses a 15-day system, two in a month: The waxing phase is called the Shukla Paksha (the white part) and the waning phase is called the Krishna Paksha (the dark part):