- One hour (1h) is 60 minutes, and one day is 24 hours (24h).
- In order to read the time, one day can be divided into two 12-hour (12h) periods, both for analog clocks (with hands) and digital clocks, or in a single 24-hour (24h) period in the case of digital clocks.
- The electronic clocks show the time such as: "hh:mm ss", where hh represent the hours, mm represent the minutes and ss the seconds. The electronic clocks can use the two 12-hour (12h) periods or the 24-hour (24h) period time representation (time keeping system).
- In the case of 24h system the time runs continuously between 00:00 (at midnight), it passes by the 12:00 (at noon) to almost reach again the midnight at one minute before zero, at 23:59.
- In the case of 12h time system the midnight is 12:00 a.m. while the noon is 12 p.m.
- The equivalent of the 24-hour system 11:00 hours in the 12-hour system is 11:00 a.m. (the same). The equivalent of 13:00 hours is 01:00 p.m. (subtract 12 from 13).
- a.m. = ante meridiem (morning, before noon).
- p.m. = post meridiem (after the noon).
- When we say what the time is we usually say only the hours and the minutes since the seconds change too fast to be mentioned. Of course, there are situations where precision is of importance and then we must mention the seconds too (or even fractions of seconds ...).

- Day is divided into two 12-hour periods beginning alternately at midnight and noon, in the case of the electronic watches that display the time in the 12h system, or in a single period of 24-hour, in the case of the watches that display the time in the 24 system.
- a.m. = ante meridiem (morning, before noon).
- p.m. = post meridiem (after the noon).
- When telling time the hours are said first then the minutes.
- In the digital format, when the minutes are said, they always indicate how many minutes have passed over the current hour.
- The word "minutes" is usually omitted when the time is expressed in the digital format.

**Example 1**- the number of hours is less than 12 (in the morning): if an electronic clock shows**08:43**...- In the 12h digital system we will say that it is "eight forty-three a.m.". (add a.m. since time is in the morning).
- In the 24h digital system we will say that it is "eight forty-three".

**Example 2**- the number of hours is more than 12 (after noon): if an electronic clock shows**19:15**...- In the 12h digital system we will first have to do a preliminary operation, to find out what is the number of hours. Knowing that one day is 24 hours, and the day is divided into two 12-hour periods, we find the current number of hours by subtracting: 19 - 12 = 7. So we will say it is "seven fifteen p.m." (add p.m. since this time is in the afternoon).
- in the 24h digital system we will say that it is "nineteen fifteen".

- Day is divided into two 12-hour periods beginning alternately at midnight and noon.
- When telling time the number of minutes is said first then the hours.
- When the minutes are said they either indicate how many minutes have passed over the current hour, or how many minutes are there up to the next hour. If more than 30 minutes have passed over the current hour, the minutes will indicate the number of minutes remaining until the next hour, otherwise they'll indicate the number of minutes that have passed over the current hour.

**Example 1**- the number of minutes is less than or equal to 30 and the number of hours is less than 12 (in the morning). If an electronic clock shows**08:10**, then we will say that the time is in the Civil Time...- In American English (Am-En): "ten [after | past] eight in the morning". [ | ] Either could be used.
- In British English (B-En): "ten past eight in the morning".
- The word "minutes" is not said when the number of minutes is a multiple of 5 (0, 5, 10, 15, 20, 25, ...).

**Example 2**- the number of minutes is equal to 15 and the number of hours is less than 12 (in the morning). If an electronic clock shows**08:15**, then we will say that the time is...- In American English (Am-En): "a quarter [after | past] eight in the morning".
- In British English (B-En): "a quarter past eight in the morning".
- 15 minutes is a quarter of an hour, 15 minutes = 60 minutes / 4.

**Example 3**- the number of minutes is equal to 30 and the number of hours is less than 12 (in the morning). If an electronic clock shows**08:30**, then we will say that the time is...- In American English (Am-En): "half [after | past] eight in the morning".
- In British English (B-En): "half past eight in the morning".
- 30 minutes is half an hour, 30 minutes = 60 minutes / 2.
- We always say: "half [after | past] the hour" and never "half [of | till | until | before | to] the hour".

**Example 4**- the number of minutes is more than 30 and the number of hours is less than 12 (in the morning). If an electronic clock shows**08:43**, before we could say what the Civil Time is, we must do two preliminary steps:- 1) We will have to find out how many minutes are left up to the next hour. Since there are 60 minutes in one hour, subtract the number of minutes out of 60: 60 - 43 = 17.
- 2) Because we will show the number of minutes remaining up to the next hour, we will have to add one extra hour to the current time to find the next hour: 8 + 1 = 9.
- So we say that 08:43 hours is...
- In Am-En: "seventeen minutes [of | till | until | before | to] nine in the morning".
- In B-En: "seventeen minutes to nine in the morning".

**Example 5**- the number of minutes is 45 and the number of hours is less than 12 (in the morning). If an electronic clock shows**08:45**, then we say that the time is...- In Am-En: "a quarter [of | till | until | before | to] nine in the morning".
- In B-En: "a quarter to nine in the morning".
- 15 minutes is a quarter of an hour, 15 minutes = 60 minutes / 4.

**Example 6**- the number of minutes is less than or equal to 30, and the number of hours is more than 12 (after lunch). If an electronic clock shows**19:15**we will first have to run a preliminary step in order to find out the number of the hours.- A day is 24 hours, and the day is divided into two 12 hour periods, we find out the current number of hours by doing the subtraction: 19 - 12 = 7.
- So we're going to say that 08:45 is...
- In Am-En: "a quarter [after | past] seven".
- In B-En: "a quarter past seven".
- 15 minutes is a quarter of an hour, 15 minutes = 60 minutes / 4.

**Example 7**- the number of minutes is more than 30, and the number of hours is more than 12 (after lunch). If an electronic clock shows**19:43**, before we could say what time it is, we first have to do three preliminary steps.- 1) Having 60 minutes in an hour, find out how many minutes are left up to the next hour by doing the substraction: 60 - 43 = 17.
- 2) Since a day is 24 hours and it is divided into two 12-hour periods, find out the current number of hours by doing this subtraction: 19 - 12 = 7.
- 3) Because we will show the number of minutes remaining until the next hour, we will have to add one extra hour to the current time to find the next hour: 7 + 1 = 8.
- So we say that the 19:43 is...
- In Am-En: "seventeen minutes [of | till | until | before | to] eight in the evening".
- In B-En: "seventeen minutes to eight in the evening".

**Example 8**- if an electronic clock shows**00:00 (at midnight)**, before we could say what time it is, we first have to do two preliminary operations.- 1) The time equivalent of 0 is 24: 00 = 24.
- 2) A day is 24 hours and is divided into two 12 hour periods, find out the current number of hours by subtracting: 24 - 12 = 12.
- We're going to say that 00:00 time is...
- In Am-En: "twelve [o'clock | sharp | on the dot] at midnight".
- In B-En: "twelve o'clock at midnight".

- The 12 hour system could create an unnecessary source of errors (as to which of the two iterations of a given hour is occurring in the 12-hour system) in areas where errors are not acceptable, ie. military, police, medical, emergency services. The Military Time is even used by individuals who live and work in polar environments (where a polar day could last for several months).
- In the Military Time, the day is made up of a single 24-hour period beginning at 00:00 midnight. Each hour in the day is unique and cannot be confused with any other.
- There are no semicolon between the numeric hours and minutes, ie. instead of 24h digital time 19:55 you write 1955 Military Time.

**Example 1**: If the Military Time is 1119 hours, in words you say "eleven nineteen hours".- The Civil Time is 11:19 = nineteen minutes [after | past] eleven in the morning.
- The electronic time in the 12h system is 11:19 a.m. = eleven nineteen a.m.
- The electronic time in the 24h system is 11:19 = eleven nineteen.
- [|] Either could be used.

**Example 2**: If the Military Time is 1819 hours, in words you say "eighteen nineteen hours".- The Civil Time is 6:19 = nineteen minutes [after | past] six in the morning.
- The electronic time in the 12h system is 06:19 p.m. = six nineteen p.m.
- The electronic time in the 24h system is 18:19 = eighteen nineteen.
- [|] Either could be used.

**Example 3**: If the Military Time is 1400 hours, in words you say "fourteen hundred hours".- The Civil Time is 02:00 in the afternoon = two [o'clock | on the dot | sharp] in the afternoon.
- The electronic time in the 12h system is 02:00 p.m. = two hundred p.m.
- The electronic time in the 24h system is 14:00 = fourteen hundred.
- [|] Either could be used.

**Example 4**: If the Military Time is 0500 hours, in words you say "zero five hundred hours".- The Civil Time is 05:00 in the morning = five [o'clock | on the dot | sharp] in the morning.
- The electronic time in the 12h system is 05:00 a.m. = zero five hundred a.m.
- The electronic time in the 24h system is 05:00 = zero five hundred.
- [|] Either could be used.

**Example 5**: If the Military Time is 0000 hours (or 2400 hours), in words you say "zero hundred hours" or "twenty-four hundred hours".- The Civil Time is 12:00 at midnight = twelve [o'clock | on the dot | sharp] at night.
- The electronic time in the 12h system is 12:00 a.m. = twelve hundred a.m.
- The electronic time in the 24h system is 00:00 = zero hundred.
- [|] Either could be used.

- This is the digital time in the 12h system. See the paragraph above. But instead of a.m. or p.m. one could also say "in the morning", "in the afternoon", "in the evening" or "at night"...
**Example:**If the time is 17:46 then the number of hours is: 17 - 12 = 5 p.m. Time in words is: "five forty-six [p.m. | in the afternoon]". [ | ] Either could be used. p.m. = post meridiem (after the noon).