# DMY Hour-Minute Datetime

Key: `datetime.timestamp.dmy_hm`

Day/Month/Year datetime with 24-hour clock. Day-first ordering (DD/MM/YYYY). Used across the EU and many Commonwealth countries.

Page: <https://meridian.online/docs/projects/finetype/types/datetime/timestamp/dmy_hm>

Format: `%d/%m/%Y %H:%M`

Samples: `15/01/2024 10:30`, `31/12/2019 23:59`

## Background

### Origin

In the United Kingdom, dates are traditionally and most commonly written in day–month–year order.[[1]](https://en.wikipedia.org/wiki/Date_and_time_notation_in_the_United_Kingdom) In British usage, the time can be written using either the 24-hour clock, as in 23:59, or the 12-hour clock, as in 11:59 p.m.[[1]](https://en.wikipedia.org/wiki/Date_and_time_notation_in_the_United_Kingdom) The 24-hour clock is the most commonly used time notation in the world today.[[2]](https://en.wikipedia.org/wiki/24-hour_clock) The most commonly used separator between hours, minutes and seconds is the colon, which is also the symbol used in ISO 8601.[[2]](https://en.wikipedia.org/wiki/24-hour_clock) Read this format as two national writing habits joined by a space, a day-first date and a 24-hour clock time, rather than as a data standard in its own right. (Meridian's view)

In the Unicode CLDR locale data, the short date pattern for French (fr) is dd/MM/y.[[3]](https://raw.githubusercontent.com/unicode-org/cldr-json/main/cldr-json/cldr-dates-full/main/fr/ca-gregorian.json) In the Unicode CLDR locale data, the short time pattern for French (fr) is HH:mm.[[3]](https://raw.githubusercontent.com/unicode-org/cldr-json/main/cldr-json/cldr-dates-full/main/fr/ca-gregorian.json)

### Use

Day-first notation contrasts with date notation in the United States, where the month is placed first, leading to confusion in international communications.[[1]](https://en.wikipedia.org/wiki/Date_and_time_notation_in_the_United_Kingdom) A value such as 05/04/2024 10:30 reads as a valid timestamp in either order, so one value on its own cannot tell you whether a file is day-first or month-first. (Meridian's view) Look across the whole column for a first number above 12, and check the publisher's documentation when none turns up. (Meridian's view)

Python's strftime and strptime directives define %H as the hour on the 24-hour clock as a zero-padded decimal number.[[4]](https://docs.python.org/3/library/datetime.html) Python's strftime and strptime directives define %M as the minute as a zero-padded decimal number.[[4]](https://docs.python.org/3/library/datetime.html) DuckDB's strptime(text, format) function converts strings to timestamps according to the specified pattern.[[5]](https://duckdb.org/docs/current/sql/functions/dateformat.html) The DuckDB documentation gives strptime('02/03/1992', '%d/%m/%Y') as an example, returning 1992-03-02 00:00:00.[[5]](https://duckdb.org/docs/current/sql/functions/dateformat.html) DuckDB lets a timestamp format be specified during CSV parsing with the TIMESTAMPFORMAT option, in the COPY statement or in the read\_csv function.[[5]](https://duckdb.org/docs/current/sql/functions/dateformat.html)

### Where you'll meet it

Transport for London's cycle hire journey data extract for 7 to 13 March 2018 writes its Start Date and End Date columns in the form 10/03/2018 12:14.[[6]](https://cycling.data.tfl.gov.uk/usage-stats/100JourneyDataExtract07Mar2018-13Mar2018.csv)

## Sources

1. [Date and time notation in the United Kingdom - Wikipedia](https://en.wikipedia.org/wiki/Date_and_time_notation_in_the_United_Kingdom) — secondary source
2. [24-hour clock - Wikipedia](https://en.wikipedia.org/wiki/24-hour_clock) — secondary source
3. [cldr-json/cldr-dates-full/main/fr/ca-gregorian.json](https://raw.githubusercontent.com/unicode-org/cldr-json/main/cldr-json/cldr-dates-full/main/fr/ca-gregorian.json) — documentation
4. [datetime — Basic date and time types — Python 3.15.0 documentation](https://docs.python.org/3/library/datetime.html) — documentation
5. [Date Format Functions – DuckDB](https://duckdb.org/docs/current/sql/functions/dateformat.html) — documentation
6. [100JourneyDataExtract07Mar2018-13Mar2018.csv](https://cycling.data.tfl.gov.uk/usage-stats/100JourneyDataExtract07Mar2018-13Mar2018.csv) — dataset