Many groups have several DATE Variables that can be used to describe the time period that the metadata or ancillary data represents.
Dates should be entered at the precision known and most suitable to the observation. Supported precision include year, month, day, and minute in ISO formats: YYYY, YYYYMM, YYYYMMDD, YYYYMMDDHHMM.
DATE or DATE_START / DATE_END
Either a single DATE or a DATE_START / DATE_END pair is required. Do not enter both for the same observation.
- Use DATE when the observation represents a single point in time. Typical resolutions used are a year, month, or day: YYYY, YYYYMM, YYYYMMDD.
- Use DATE_START / DATE_END when the observation represents a period of time. Start and end dates are often used when observations are collected as part of a campaign. Typically resolution is reported with day (YYYYMMDD), but month is also common (YYYYMM).
Notes:
- Do not enter DATE and DATE_START for the same observation. See “Mutually-exclusive variables cannot be submitted together” on BADM Basics: Key Concepts.
- Within a BADM group (e.g., HEIGHTC), different observations cannot be reported for the same DATE and DATE_START. See “Rules for unique variable combinations Ⓒ” on BADM Basics: Key Concepts.
- DATE_END must be reported if DATE_START is reported.
DATE_UNC
Uncertainty in the DATE or DATE_START / DATE_END is an optional variable that can also be reported.
Date uncertainty is most commonly reported when the single DATE variable is used.
Report a date uncertainty that is commensurate with the DATE or DATE_START / DATE_END reported. For example if a day is reported for the DATE, date uncertainty should be on the order of days rather than months or years. If a year is reported for the DATE, date uncertainty should be greater than a year.