Stopwatch
An analog, handheld timepiece used to measure elapsed time, as for athletic sprints. Appearance varies across platforms, but depicted with two or more control buttons on its top.
Used for various content concerning time. Not to be confused with ⏰ Alarm Clock or other clock emojis.
Stopwatch was approved as part of Unicode 6.0 in 2010 and added to Emoji 1.0 in 2015.