what about atraf annahar

Atraf is pluriel, can that mean annahar is pluriel ?
Anaa l layl is pluriel , can anaa is a pluriel for Aan , wich bring us to layl is pluriel also ? just as a half of the night is called night, a part of the night is called night , but if we want to call a single night we say laylah, and if we call a definite number of nights, we say layali, like layalin aachr, but if we talk about layl in forever we say layl

is this verse talking about everything in pluriel ?
because if it is the case, than, we're supposed to do salat forever, all our life than, because i thaught about doing salat and allah never gave a command to do it everyday and all your lives , except in Isa when he said i do salat ma doumtou hayya
I don't know, it makes sens to me,

For i know that is called Ishrak and is duluk that happens and atraf nahar are pluriel form of from duluk to ghassak and before ishrak , so is this verse explaining the two tiimes of salat in pluriel expressions?