"There is never anyone there on Sundays."
Translation:Il n'y a jamais personne le dimanche.
le dimanche means "on Sundays".
Quelqu'un isn't used in negative clauses. For example, you would say « Quelqu'un est là » for 'Someone is there,' but « Personne n'est là » for 'No one is there,' and « J'ai dit quelque chose à quelqu'un » for 'I said something to someone,' but « Je n'ai rien dit à personne » for 'I didn't say anything to anyone.'
Yes, I am confused as well although some commenters claim that the second "there" is in the sentence.
THERE is never anyone (there?????) on Sundays? Il y a there is/there are, so where is the second "there" coming from?
I would suggest the best translation of this sentence is There is never anyone on Sundays