Looks definitely like sunburn. Does this dry out a lot between waterings? Not being hydrated would also help lead to sunburn.
I water my ginkgo daily...but it also is in bonsai soil. So well draining.
You can remove the real brown fried ones. The others leave. They serve a purpose. You don't want to degoliate a ginkgo so I would really try to keep most still intact.
You should water when the soil is dry, not on a schedule. I can't see what kind of pot/soil it is in but I think Athens is pretty warm now.
Keep it watered well and out of the worst sun.
Sun damage, shift to partial shade, remove damaged leaves and maintain proper watering. This could be caused by heat wave or a plant moved from shadier more protected location to full sun without the chance to adapt to the new conditions.