Evelyn Venegas/Assignment # 3/24/7

1. Where is the 12-hour clock still used?
Australia,Canada (except Quebec and other Francophone communities),Colombia, Egypt,Pakistan,India,Malaysia,New Zealand,Philippines,United States of America.

2. What does a.m and p.m. mean?
A.M: in the morningP.M: in the night

3. Although using the 12-hour clock in speech is very common, using a.m. and p.m. is not common. What time expressions do we use to distinguish between, for example: the difference between 2am and 2pm?
Post Meridiem ( After Noon). Am= Ante Meridiem ( Before Noon)

4. What are some of the problems with using a 12-hour clock?
Since the Latin word meridies means noon or midday, it is illogical to refer to noon as either "12 a.m." or as "12 p.m.". On the other hand, midnight could logically be called either "12 p.m." or "12 a.m." ; "x a.m." no longer means "x hours before noon", but "x hours into the day but before noon" or "x th hour before noon".

5. What is the confusion about midnight and noon?
The disadvantages commonly voiced in comparing the 12-hour notation to the 24-hour clock are:confusion about the correct notation for noon and midnightconfusion about the difference between midnight at the start and end of a given dateThe rollover from 12 to 1 happens an hour later than the change between a.m. and p.m.The lexicographical order does not match the chronological order.It is more complicated to implement in software and digital electronics.Typographically, the a.m. and p.m. terms require more space.

6. What does rounding off mean, in informal speech? Give 3 examples.
twenty-four to six -twenty-four past five-five twenty-four-Half-way to fivehalf-way to five".

7. Name 5 advantages of the 24-hour clock.
There is no ambiguity between midnight at the start and end of a date, whereas confusion exists on this issue with the 12-hour system. *The duration of time intervals is easier to see in the 24-hour notation. From 10:30 a.m. till 3:30 p.m. is 5 hours. From 10:30 till 15:30 indicates this more clearly. *The 24-hour notation does not require the suffix "a.m." or "p.m.", making it shorter, which saves space in tables. *24-hour notation in string form is easier for computers to sort, and it's also less time expensive to convert the time from string form to Unix time. *The transition from 23:59 to 00:00, provides a clear reminder that a new date starts, which is less obvious in the equivalent 11:59 p.m. to "12:00 a.m." transition.

8. Name 5 advantages of the 12-hour clock.
Typical analog clock faces are divided into 12 hours, with each hour point in addition serving as five minutes, which lines up well with a 12-hour system. More rarely used 24-hour analog dials necessarily have smaller spaces between hours, which can be harder to read, particularly on a small dial. *Restricting the hour numbers to the range from 1 to 12 can accommodate a preference for monosyllabic words, which applies to many European languages (including English, French, German, Danish, Swedish, Norwegian), in which most of the 12 are monosyllabic, opposed to the 13–24 range, in which none of those numbers are monosyllabic. *The use of 12 rather than 0 for the first hour of each period avoids using a leading zero. *Clocks with a chime universally chime between hours 1 to 12, but deviate in approach for hour 0 and hours 13 to 23. While it is not possible to chime zero times, clocks may in fact chime at the end of 23:59 and again at 1:00.[citation needed] *Sunrise and sunset are, roughly, centered around 6:00 in their respective halves of the day during the course of a year. That is, at an equinox, and disregarding civil time in favor of apparent solar time, the sun will rise at 6:00 a.m. and set at 6:00 p.m. At the local summer solstice, the sun might rise at, say, 4:00 a.m. and set at 8:00 p.m., and vice-versa (8:00 a.m. to 4:00 p.m.) at the local winter solstice. There are many reasons why this is not exact (atmospheric refraction, the fact the sun is a disc and not a point, time zones, daylight saving time, and so forth), but it still can be a useful approximation under certain conditions.

9. Describe the time and date notation for the following countries:
a. Australia: date format is d/m/yyyy
b. Canada: d/m/y except Quebec y/m/d often use the 24-hour clockc.
c. Ireland: d/m/y When talking about the time, it is usually said in traditional 12-hour formatd. d.South Africa: d/m/y 24 hours.e.
e. United Kingdom: d/m/y 24 hoursf.
f. United Kingdom:d/m/y 24 hoours

10. What is ISO 8601?
International standard ISO 8601 defines unambiguous written all-numeric bigendian formats for dates, such as 1999-12-31 for December 31, 1999; and time, such as 23:59:59 for 23 hours, 59 minutes, and 59 seconds (one second before midnight).