Can someone help correct me: 

2 haftaya kadar gelebilirsin

Does it mean: you can come for up to two weeks or you can come in two weeks time

Thank you

Please????

May mean both...I would not guess on it, your friend has a weird Turkish.

Better ask for a clarification.

Thanks anyway

You can come for up to two weeks = 2 haftaya kadar gelebilirsin.

You can come in two weeks = 2 hafta içinde gelebilirsin.

up to = -a(e) kadar.

So his Turkish is not that weird then )))).

thank you very much