"नेहा रविवार को जायेगी ।"

Translation: Neha will go on Sunday.

[tizerzert]

Why ko ?

[PolyglotCanavar]

They use ko instead of me for Days. Similar to how in/on/at are different in English.

[DennisLDuolingo]

Fun fact: रविवार comes from रवि which is Hindi for Sun, by using Greek astrology, similarly like the names of the day of the week in many languages, like English Sunday.