"आप मंगलवार को खेलते हैं।"

Translation: You play on Tuesday.

[Oinophilos]

Perhaps, then, the translation should be "on Tuesdays" as without context it sounds more like a future appointment. It seems, though, that "on Tuesday" alternates with "on Tuesdays" or simply "Tuesdays" all with the same meaning given the right context.

[Oinophilos]

I take it this means "You play every Tuesday"; can it also mean "You are scheduled to play this coming Tuesday," as an English speaker might understand the translation?

[vinay92]

It means 'You (generally) play on Tuesdays'. The latter meaning does not come across in the Hindi sentence. You have to say आप मंगलवार को खेलेंगे - 'You will play on Tuesday'.

[Elliott728894]

it kinda looks like the days of the week are like in europe named after religious items. correct ?

[vinay92]

They are named after the sun, the moon and the five planets that are observable with the naked eye. Of course, all these celestial objects are also personified as deities in Hindu mythology.

सोमवार - Moon (same as 'Monday')
मंगलवार - Mars
बुधवार - Mercury
गुरुवार (बृहस्पतिवार) - Jupiter (The planet/diety is called बृहस्पति but is given the title गुरु - 'teacher')
शुक्रवार -Venus
शनिवार - Saturn (same as 'Saturday')
रविवार - Sun (same as 'Sunday')

The 'planet' to 'day of the week' relationship is the same as in many other languages.