Is this dialogue OK?
(for an appointment)
Person A - What time would be best for you?
Person B - Anytime would be okay for me. / Anytime would be all right for me.

Question

Answer

Hi Sinem,

Either answer would be common and understood.

In addition, it is common in the U.S. to say, "Anytime would work for me.".

More informal (also in the U.S.), but also very common, is to say, "Whatever you have works".

Have a great day!