Como eu digo "desde os tempos antigos" em inglês

Português: desde os tempos antigos, desde o início dos tempos, desde há muito tempo, desde tempos imemoriais.
Inglês: since ancient times, since the year dot, since God knows when, since immemorial times.

Exemplo 1: 1781: Uranus was the first new planet found since ancient times – and William Herschel’s momentous discovery ushered in a golden age of astronomy. Ref. thesun.co

Exemplo 2: People have been doing it since the year dot, getting publicity through the royals. They will make outrageous comments and unless it's libellous, the royals won't do anything about it. Ref. bbc

Exemplo 3: For the first time since God knows when,
It is not the power-hungry territorial countries
Spreading unrest and even fear. Ref. bishopeton.org

Exemplo 4: (...)alerted by an atavistic instinct and a deep-rooted cultural heritage which, since immemorial times alerts females that they should not be walking alone (...) Ref. delcantochambers

OBS.: Encontra-se também since times immemorial.

Exemplo 5: Since times immemorial, people involved in the struggle for a better world have given expression to their aspiration not only in political texts and deeds, but also in artistic ways. Ref. culturematters.org

Cf. Como dizer "Desde que o mundo é mundo" em inglês