The publication date field is a required field. By default, it is set to the date the draft was created. If your upload was previously published somewhere else (e.g. a journal article), please use the date of the first publication. Note, that in addition to the publication date, we keep track of the date a record was uploaded to the repository.
For older content you may not always know a precise publication date. In these cases you may use both imprecise dates and date ranges (using the Extended Date Time Format Level 1).
Reduced precision for year and month:
2023-09 refers to the month of September 2023.
Reduced precision for year:
2023 refers to the calendar year 2023.
2023-01-01/2023-09-23 refers to the time interval beginning January 1st 2023 and ending on September 23rd 2023.
Time interval imprecise:
1939/1945 refers to the time interval beginning sometime in 1939 and ending sometime in 1945.