Divisions

Spans of time are broken down into smaller units for easier tracking of the passage of time.

Year: Annual pattern of solar orbit (vernal equinox, summer solstice, autumnal equinox, and winter solstice). There are 360 days and 12 months in the standard calendar.
Months: Varies due to existence of two lunar bodies with different orbital periods. Most calendars follow the silver moon. There is a supercyclic pattern measured from when the moons are in conjunction.
Ten-Day and Five-Day: Analogous to weeks. three or six per month respectively.
Day: Position of sun in sky (sundials), broken into six watches. Individual days are not named but rather numbered.
Watch: Broken into four 1-hour periods.
Hour: 60 minutes.

Devices

Instruments and tools to keep track of the time of day or to measure the passing of hours.
Sand Glasses: Sand glasses of various duration are employed where available, but due to variance in manufacture they are not standardized.
Candles: Candles of fixed size and reasonable burn-times are used by some to track the passing of the hours, but difficult to tell exact time to any fractions smaller than 1/12th (5 minutes).
Clocks: Mechanical, water-clocks, weighted pendulums and the like are not yet in use, outside of a few cases.

Regional differences in climate make for variance in calendar month names but here's two:

There is also a sun-sign system noted by the daily progression of the sunrise relative to a series of constellations.