Calendars - Clocks - Sequence - Rate - Duration by Chris Nitert. The study of time involves much more than reading clocks. In these engaging activities, students explore sequencing, recording and timing events, seasons and calendars, 12 hour and 24 hour clocks, duration and estimation, and time zones along with many other subjects. The varied activities involve math and language arts skills and provide various options for introducing, reinforcing and teaching time-related subjects. This series of activities can provide a thematic unit of study or be used to support ongoing curricula. 48 pages.