Time.is

Time.is gives you extremely accurate time for any time zone.
Features:
- Synchronization to atomic clock time with an accuracy down to ±5 milliseconds
- Instant time conversion/meeting planner/world clock with 7 million locations
- Always up-to-date time zone database, automatically adjusted when time zone rules are changed
- 44 languages
- Sunrise time, sunset time and day length
- Beautiful calendar with interval calculation
- Word clock
- Dark/light mode
- Several time and date formats (seconds on/off, 12/24 hour mode)
- Intuitive, gesture driven interface
- Elegant, minimalistic design
- Designed to take advantage of large iPad screens
- Looks great in both portrait and landscape format
- Small file size
- Works offline (except synchronization and search)
- No ads
This app synchronizes to the web site Time.is, which is a favorite among clock collectors and time enthusiasts. Time.is was nominated for the Webby Awards in 2012 (Best Visual Design - Function), and has been featured by Mashable, Lifehacker and Hackernews.