Khan Academy
Khan Academy: Converting Units of Time Review
Resource reviews seconds, minutes, and hours, and how to convert between them then provides practice problems.
Other
Conversions for Time Measurement
This site allows you to convert various time measurements. Example seconds to days.
TeachEngineering
Teach Engineering: Robo Clock
Students learn various topics associated with the circle through studying a clock. Topics include reading analog time, understanding the concept of rotation (clockwise vs. counter-clockwise), and identifying right angles and straight...