[Grammar] at Saturday night?

[heyt]

Hello,

I think I know the rules about prepositions of time, but could someone help me find out the rule about the phrase ' at night'?

For example, should I say 'I went to the cinema at Saturday night 'o r 'I went to the cinema Saturday night'?

Thank you very much,
heyt

 

[Rover_KE]

'I went to the cinema on Saturday night' or (informally) 'I went to the cinema Saturday night'.

Rover