When a landlord give an eviction notice, how long does one have before having to move out.

The eviction notice should include a date by which you must move out. What is the reason you are being evicted? What does the notice say? I believe 30 days is typical in most jurisdictions.

The vacate notice will specify how long you have untilyou have to move out. If you don't vacate by the specified deadline, then the landlord has to go to court for an eviction order. A court hearing will be scheduled. How long before the hearing is scheduled depends on local conditions. At the hearing the court will specify another deadline by which you have to vacate or be physically put out.

But you really don't want to have an eviction on your record as it will make it harder to find new lodgings.