Ya media semana

[ROBINDESBOIS]

Already, mid-week.
Already, the midle of the week .
THe second one a bit stilted , isn´t it ?
Are both OK? None?
Likewise with:
Mid-month
Mid-year
????

[Tomisimo]

Both "mid-week" and "the middle of the week" are fine. For mid-month and mid-year, we would normally name the month and year:

mid-November
mid-2009