Greece has hundreds of pharmacies, but most keep standard business hours: roughly 8:30 to 14:00, then again from 17:30 to 21:00 on weekdays. On weekends and at night, the vast majority are closed.

To ensure that medication and emergency supplies are always available, Greek law requires pharmacies to take turns staying open outside normal hours. Each day, a specific set of pharmacies called efimeries (εφημερίες) must remain open around the clock. The roster rotates daily so no single pharmacy is always burdened.

In Kos, the pharmacies on duty are published daily by the local pharmacy association. This page fetches that data automatically every hour, so the list you see above is always current.