Alguien hace algo x tiempo: Someone HAS DONE something FOR x time.

The following grammar structures are difficult to translate into English:
Alguien hace (present simple) algo ...  x tiempo.
Alguien ha hecho (present perfect) algo en x tiempo.
Alguien hace/ha hecho algo desde hace x tiempo.

In English we'll use present perfect and for:
Someone ... has done ... something ... for x time.

A few examples:
Te he esperado media hora. = I've waited for you for half an hour.
No has venido en dos semanas. = You haven't come for two weeks.
Nos nos vemos desde hace años. = We haven't seen each other for years.

Another lesson on using for, since and ago.