Time and Dates

This chapter provides general guidance on the expressions of time and dates. The first and the second sections cover time and dates respectively, the third section is about how to write time and date ranges, the fourth section provides guidance on abbreviating the related terms, the fifth section provides general rules for writing time and dates in Chinese, and the last section covers additional guidelines.

Time

24-Hour System or 12-Hour System

Two systems are used to designate the hour of the day: 12-hour system and 24-hour system.

The 24-hour system is used by international standard ISO 8601. To accommodate the worldwide audience, Espressif recommends using the 24-hour time notation whenever you can.

Example

  • The meeting is set to 14:00 Beijing Time.

If you must use the 12-hour system, add the abbreviations AM (ante meridiem [i.e., before noon]) and PM (post meridiem [i.e., after noon]) to the end of the clock time.

Example

  • 6 AM = 6 o’clock in the morning

  • 10 PM = 10 o’clock in the evening

The abbreviations am and pm, a.m. and p.m., A.M. and P.M., are also acceptable.

Separator Symbols

Use a colon to separate hours, minutes, and seconds.

Example

  • 23:59:59.5 = 0.5 s before midnight

Expressing Noon or Midnight

Just using “noon” or “midnight” is sufficient to indicate noon or midnight.

Example

Preferred

Avoid

Comment

The meeting is at noon.

The meeting is at 12 PM.

12 PM is ambiguous.

Time Zone

The time in China follows a single standard time offset of UTC+08:00 (eight hours ahead of Coordinated Universal Time). The official national standard time is called Beijing Time (Chinese: 北京时间) domestically and China Standard Time (CST) internationally.

If you give time for an event that involves audience from different time zones, include the time zone and the offset from Coordinated Universal Time (UTC).

Example

  • The roadshow begins at 10:00 China Standard Time (UTC+8).

Dates

Writing Dates with the Month

  • Capitalize the names of the months, e.g., January.

  • Spelling out the names of months is recommended. When short forms are needed in tables, graphs, and other locations, use their three-letter abbreviations without dots, e.g., Apr, May.

  • Using ordinal numbers to indicate a date is NOT recommended, e.g., May 13th.

Writing Dates with the Month and the Year

  • When referring to a specific date with the month and the year, use the format “month day, year” (e.g., July 31, 2010). Place a comma before and after the year if it is not at the end of a sentence.

    Example

    • On July 22, 2019, Espressif went IPO.

    Note that a comma is used to set off the year in exact date. If there is no exact date, no comma is used. e.g., In July 2019, Espressif went IPO.

  • There may be times when it is appropriate to use other date formats besides the recommended “month day, year” style. For instance, “day/month/year” (e.g., 11/Nov/2018) may be used in Excel. When you use a certain date style, make sure that it is human readable and consistent across the document. Avoid using any formats that produce ambiguities or hinder comprehension. Below is a list of acceptable date formats:

    Acceptable Date Formats

    Acceptable Date Format

    Example

    Comment

    day month year

    • 11 November 2018

    • 11/November/2018

    • 11-November-2018

    Do not truncate the year to two digits unless space is restricted.

    year month day

    2002 April 23

    [year][month][day] all-numeral style

    • 20180801

    • 2018-08-01

  • The following formats are NOT acceptable to indicate a date:

    Non-acceptable Date Formats

    Not Acceptable Date Format

    Example

    Comment

    [day]/[month]/[year] all-numeral style

    01/02/2017

    01/02/2017 can be interpreted as February 1, 2017, or as Jan 2, 2017.

    [month]/[day]/[year] all-numeral style

    01/02/2017

Writing Days of the Week

  • Capitalize the names of the days of the week, e.g., Monday.

  • Spelling out the days of the week is recommended. When short forms are needed in tables, graphs, and other locations, use their three-letter abbreviations without dots, e.g., Mon, Tue.

  • When giving a date with both days of the week and month or year, use a comma after days of the week to ensure readability.

    Example

    • The meeting planned for Monday, February 24, 2020, has been postponed.

  • Avoid referring to week by week number of the year. Instead use specific date when the week starts.

    Example

    • Testing will be done during the week of February 24, 2020.

  • According to the International standard ISO 8601, Monday is the first day of the week and Sunday the last day of the week.

Time and Date Ranges

Use the en dash to indicate a time or date range, without spaces before and after, e.g., 11:00–13:00, July 29–July 31, 2008–present. The en dash indicates up to and including, or through.

Optionally, use “from” (followed by “to”) or “between” (followed by “and”) to indicate a period of time, e.g., from 11:00 to 13:00, between midnight and 2:00, between 2018 and 2020.

But do not mix the en dash with words e.g., do not use: from 11:00–13:00, between 2018–2020.

See also Section When to Use En Dashes.

Acronyms and Abbreviations

The following acronyms and abbreviations to indicate time are either recognized in the International System of Units (SI) or acceptable in various kinds of literature:

Acronyms and Abbreviations for Time and Dates

Acronyms and Abbreviations

Definition

Example

24/7

24 hours a day, 7 days a week year(s)

A 24/7 support program

Y or yr.

year(s)

12Y = 12 years = 12 yrs.

mo.

month(s)

3 mos. = 3 months

d or d.

day(s)

5 d = 5 days

h or hr.

hour(s)

27 h = 27 hours = 27 hrs.

min or min.

minute(s)

30 min = 30 minutes = 30 mins.

s or sec.

second(s)

4 s = 4 seconds = 4 secs.

Days of the Week

Sun

Sunday

–

Mon

Monday

–

Tue

Tuesday

–

Wed

Wednesday

–

Thu

Thursday

–

Fri

Friday

–

Sat

Saturday

–

Months

Jan

January

–

Feb

February

–

Mar

March

–

Apr

April

–

May

May

–

Jun

June

–

Jul

July

–

Aug

August

–

Sep

September

–

Oct

October

–

Nov

November

–

Dec

December

–

  • If the numeric value involves only one unit of time, insert a space between the number and symbol. If the value calls for more than one unit, set the numbers and symbols close.

    Example

    • 3.3 h

    • 3h20min

    • 3h20min14.6s

  • Use the acronyms and abbreviations for time cautiously. They may mean different things in different context. For example, “Y” is also the abbreviation for measurement unit “yotta”. Avoid using any acronyms or abbreviations that produce ambiguities or comprise comprehension.

Time and Dates in Chinese

  • Both 12-hour and 24-hour clock formats are used in Chinese context. For example, 11:00 = 上午 11:00, 17:30 = 下午 5:30, 21:00 = 晚上 9 点.

  • The normal form of days of the week is 星期几, e.g., 星期一. The abbreviation for days of the week is 周几, e.g., 周一.

  • The full form of the names of months in Chinese uses characters, e.g., 一月. The abbreviated form uses numerals, e.g., 1 月.

  • The default long date format in Chinese is YYYY 年 MM 月 DD 日 or YYYY 年 M 月 D 日, e.g., 2020 年 02 月 02 日 or 2020 年 2 月 2 日. The default short date format in Chinese is YYYY/MM/DD or YYYY/M/D, e.g., 2020/02/02 or 2020/2/2.

Additional Guidelines

Be specific if using months or years when exact dates or periods are important.

Example

Preferred

Avoid

Comment

Beta version of software will be released at the end of May 2020.

Beta version of software will be released in May 2020.

With the “Avoid” version user will expect to have the software at the beginning of May while developer really meant the end of May.

Provide feedback about this document