DATE
Many groups require DATE 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.
Typical resolutions used for DATE are year, month, or day: YYYY, YYYYMM, YYYYMMDD.
DATE_UNC
Uncertainty in the DATE is an optional variable that can also be reported.
Report a date uncertainty that is commensurate with the DATE 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.