Best Time Zone Conversion Apps for iPhone (2026)

For this list we ask the App Store the same searches a person would, in several countries, and keep every app it returns. A model reads each app's listing and rejects the ones that only mention the use case. Every app that stays is scored out of 100 from four parts, each 0 to 100 and averaged: its App Store rating, how many people rated it, where the App Store itself ranks it for this list's searches, and how recently its current version shipped. An app showing Apple's Editors' Choice badge gets a fifth part of 100, which can only lift its score. Apps whose maker has verified ownership get a small score component, because an active maker is a sign the app is kept up to date. It never decides a tier on its own. Updated daily. Tiers follow fixed score bands: S from 90, A from 80, B from 70, C from 60, D from 50, F below. On a list of 20 or more ranked apps, a tier from S to D takes in new apps only up to a quarter of the top 40: an app pushed out of a full tier falls to the next tier with room, and F takes the rest. Read the full method →