According to Oxford dictionary 2011 release, Time is a measure in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them.
According to Google's dictionary, time is 'the indefinite continued progress of existence and events in the past, present, and future regarded as a whole'. Time is considered as the 'fourth dimension' among three spatial dimensions of 'our' universe.
How is Time measured
Time is measured in seconds in Standard International system as well as CG system. A second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyper-fine levels of the ground state of the cesium-133 atom.
To make time measuring fast and simple, over years many terms like 'hour', 'minute', 'day', 'month', etc have taken shape.
60 seconds = 1 minute
60 minutes = 1 hour = 3600 seconds
24 hours = 1 day = 1440 minutes = 86400 seconds 7 days = 1 week
- days = 1 month
365 days = 1 year