Time Vocabulary: Time difference hour time zones elapsed duration minute hour seconds bridging days international time years months weeks UTC Greenwich Mean time Time

Time Conversions: Time can be written as digital or analogue time, or in 24 hour time: 2:10 can be written as ‘10 past 2’ ‘a quarter to three’ can be written as 2:45 An hour is divided into 12 sections of 5 minutes each. A day is divided into 24 hours; each of 60 minutes. Each minute is 60 seconds.

Solving Time Problems: To work out time problems, it can be helpful to use a ‘clock face’.

Using Your Calculator Time calculations can be done on your calculator. The times are entered into the calculator in this order: hours, minutes, seconds. Enter the hours and press the ° ' '' key. Next enter the minutes and press ° ' '' again. Then finally enter the seconds and press ° ' '' a third time. If there are no hours to be entered, press 0 followed by the ° ' '' key, as the calculator records the information in the order hours, minutes, seconds. This one

Time Zones Earth rotates 360° in 1 day, so 360° = 24 hours 1° = 4 minutes ( 1/15 of 60 min = 4 min) Time zones (called meridians) begin at Greenwich in London (longitude 0°). The first or prime line (meridian) is the starting point for 12 time zones west of Greenwich and 12 time zones east of Greenwich. Every place within a zone uses the same time. Coordinated Universal Time abbreviated to UTC, is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean solar time at 0° longitude; it does not observe daylight saving time. For most purposes, UTC is considered interchangeable with Greenwich Mean Time (GMT), but GMT is no longer precisely defined by the scientific community. Print off time zones for theory book