> For the complete documentation index, see [llms.txt](https://standards.spdci.org/standards/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://standards.spdci.org/standards/standards-for-interoperability-interfaces/common-standards-for-interoperability-interfaces/data/data-types-and-formats/dt.com.02-string/data-formats/df.com.string.01-date_time.md).

# DF.COM.STRING.01 date\_time

### Description

This format is used to describe date or time.

### Data Type

The format date\_time has the data type [DT.COM.02 string](/standards/standards-for-interoperability-interfaces/common-standards-for-interoperability-interfaces/data/data-types-and-formats/dt.com.02-string.md).

### Data Format

[ISO 8601:2019](https://www.iso.org/standard/70907.html)  is the required format for date and type.

The standard defines various date and time formats, which are expressed using a combination of numbers and symbols. Some key elements of ISO 8601:2019 include:

**Date format:** Dates are represented in the format 'YYYY-MM-DD', where 'YYYY' represents the four-digit year, 'MM' represents the two-digit month (ranging from 01 to 12), and 'DD' represents the two-digit day (ranging from 01 to 31). For example, Date Format: '2023-07-19' (is 19 July 2023).

**Time format:** Times can be represented in either a 24-hour format or a 12-hour format with an 'AM' or 'PM' indicator. The time format is 'hh:mm:ss' for a 24-hour clock or 'hh:mm:ss AM/PM' for a 12-hour clock. For example, Time Format (24-hour clock): '15:30:00 (is 3:30 PM) and Time Format (12-hour clock): '03:30:00 PM' (is 3:30 PM).

**Combined date and time format:** ISO 8601 also allows for the representation of combined date and time information. This format is written as 'YYYY-MM-DDThh:mm:ss' for a 24-hour clock or 'YYYY-MM-DDThh:mm:ss AM/PM' for a 12-hour clock. For example, Combined Date and Time Format (24-hour clock): '2023-07-19T15:30:00' (is 19 July 2023, at 3:30 PM) and Combined Date and Time Format (12-hour clock): '2023-07-19T03:30:00 PM' (is 19 July 2023, at 3:30 PM).

**Timezone designation:** The standard includes provisions for representing time zone information. Time zone designations are indicated by adding a '+' or '-' followed by the hours and minutes offset from Coordinated Universal Time (UTC). For example: Date and Time Format with Timezone: '2023-07-19T15:30:00+02:00' (is 19 July 2023, at 3:30 PM in a timezone with a UTC+02:00 offset).


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