Specialists in Japanese Patent Translation & Japanese Deposition Interpreting Decades of Experience In-depth Subject Matter Expertise Based in Japan, Serving the World

Resources FAQ About Us Site Map For Colleagues

Japanese Patent Translation Deposition Interpreting Inquiries Clients Japanese

Home for ClientsFor ColleaguesQuick ReferencesISO Date-Time Representations ISO Date and Time Representations by William Lise Terminology Symbols used in format descriptions Indicator symbols Date Time The ISO date/time representation formats were designed to avoid confusion. If they are used properly and universally, they would achieve this goal. I have presented here those very limited parts of the ISO date/time format standards that could have application in the writing done by translators (omitting such formats as those which express the ordinal day within a year), including translators who write for the World Wide Web. The information presented herein is basically taken from ISO 8601 (Data elements and interchange formats--Information interchange--Representation of dates and times), which was established in 1988. For more details, refer to that ISO standard or to JIS X 0301-1992, which is basically a translation of the ISO standard, with the addition of sections on era names. Terminology Here are some of the terms used in discussing these date/time formats that might not be intuitively obvious. Complete representation A representation that includes all elements of the date and time related to a particular type of format Basic format A format containing the minimum required items to provide the required accuracy of representation Extended format An extension of the basic format which uses separating symbols Symbols Used in Descriptions of Formats Here are the symbols used in describing the ISO date/time formats. C Century (two digits; the thousands and hundreds places of the Gregorian year) Y Year (two digits; the tens and units places of the Gregorian year) M Month (two digits; padded with a leading zero if necessary) D Day (two digits; padded with a leading zero if necessary) h Hour (two digits; padded with a leading zero if necessary) m Minute (two digits; padded with a leading zero if necessary) s Second (two digits; padded with a leading zero if necessary) E Imperial era name (single-letter symbol) Indicator Symbols Used in Actual Date/Time Representations T Time symbol; used to indicate the beginning of the time when the date and time are combined. Z Symbol placed immediately after the time to indicate Coordinated Universal Time (UTC) - Symbol (hyphen) used to represent each element that is omitted in truncated representation. Date The examples given below will use the date of April 12th, 1985. Complete Date Representation Basic format CCYYMMDD Example 19850412 Extended format CCYY-MM-DD Example 1985-04-12 Lower-Order Truncated Date Representations (1) Specific Month Basic format CCYY-MM Example 1985-04 Extended format (None) (2) Specific Year Basic format CCYY Example 1985 Extended format (None) (3) Specific Century Basic format CC Example 19 Extended format (None) Higher-Order Truncated Date Representations (1) Specific Year, Month, and Day of Some Century Basic format YYMMDD Example 850412 Extended format YY-MM-DD Example 85-04-12 (2) Specific Year and Month of Some Century Basic format -YYMM Example -8504 Extended format -YY-MM Example -85-04 (3) Specific Year of Some Century Basic format -YY Example -85 Extended format (None) (4) Specific Month and Day Basic format --MMDD Example --0412 Extended format --MM-DD Example --04-12 (5) Specific Month Basic format --MM Example --04 Extended format (None) (6) Specific Day Basic format ---DD Example ---12 Extended format (None) Date Representations Using the Imperial Era When necessary, the imperial era can be used in the representation of the date, in which case the date is represented by a two-digit year according to the imperial era, a two-digit month, and a two-digit day, with periods between the year and the month and between the month and the day. If necessary, one of the following symbols may be prefixed to the year. M Meiji T Taisho S Showa H Heisei Basic format YY.MM.DD Example 60.04.12 Extended format EYY.MM.DD Example S60.04.12 Time The ISO time representations use the 24-hour clock, and calls for two-digit representations of the hour, minute and second. Complete Time Representation Basic format hhmmss Example 232150 Extended format hh:mm:ss Example 23:21:15 Lower-Order Truncated Time Representation When accuracy is not required, the following two-digit and four-digit time representations may be used. Basic formats hhmm hh Examples 2321 23 Extended formats hh:mm (None) Example 23:21 Time Representation Using a Decimal Point If the application makes it necessary, it is possible to use a decimal point in the hour, minute, or second. Basic formats hhmmss.s hh.mm.m hh.h Examples 232150.4 2321.84 23.364 Extended formats hh:mm:ss.s hh:mm.m (None) Examples 23:21:50.4 23:21.84 Representation of Midnight Midnight can be represented in either of following two ways. (1) Beginning of a Day Basic format 000000 Extended format 00:00:00 (2) End of a Day Basic format 240000 Extended format 24:00:00 Coordinated Universal Time (UTC) To represent Coordinated Universal Time, the time zone symbol Z is suffixed to the time, without an intervening space. The representations for the time 23:20:30 in UTC would be as follows. Basic formats hhmmssZ hhmmZ hhZ Examples 232030Z 2320Z 23Z Extended formats hh:mm:ssZ hh:mmZ (None) Examples 23:20:30Z 23:20Z Difference Between Local Time and UTC The difference between local time and UTC is indicated by suffixing that difference to the local time, with an intervening + or -, depending upon whether the local time is ahead or behind UTC, respectively. In the following, the examples used are those of the local time 15:27:46 in Geneva, which is 1 hour ahead of UTC, and in New York, which is 5 hours behind UTC. Basic formats +hhmm +hh -hhmm -hh Examples 152746+0100 152746+01 152746-0500 152746-05 Extended formats +hh:mm +hh -hh:mm -hh Examples 15:27:46+01:00 15:27:46+01 15:27;46-05:00 15:27:46-05 Note To avoid confusion with the higher-order truncated representation of the date, it is best not to use the time zone difference representation alone for zones that would require a "-" symbol. Representations That Combine the Date and the Time If an application requires that both the date and time be represented, a particular point in time is expressed by combining expressions for the date and the time, with a time-indicating symbol separating these two parts of the representation. (1) Complete Representation When combining the date and time, the letter T is placed at the beginning of time part. Just as with individual date and time expressions, hyphens and colons can be used as separators in combined time and date representations. It is also possible, with the agreement of entities to use the time/date representations, to eliminate the separating symbol (T). Basic formats CCYYMMDDThhmmss CCYYMMDDThhmm CCYYMMDDThh Examples 19850412T101530 19850412T1015 19850412T10 Extended formats CCYY-MM-DDThh:mm:ss CCYY-MM-DDThh:mm CCYY-MM-DDThh Examples 1985-04-12T10:15:30 1985-04-12T10:15 1985-04-12T10 (2) Representations Other Than Complete Representation When representing both the time and the date, it is possible to combine time and the day in truncated forms. However, the lower order of the date must not be truncated, since it is positioned in the center of the expression, adjacent to the upper order of the time (with an intervening symbol T).

www.lise.jp/datetime.html © Lise & Partners, Inc. Last modified: Monday, 12-Apr-2010 19:19:03 GMT