Recording information in this field is conditioned upon filling out the Publication Date field. The normalized publication date should be recorded following ISO 8601:1988 standard, meaning the year in four digits, and, only if present in the publication date, the month in the next two digits, and the day in the last two. When there is no month or day of publication, fill in the corresponding spaces with zeros. According to most publication standards adopted by publishers, scientific journals do not have a publication day, only month and year. If the date refers to a period of time, record the last date of the period.

Examples:

Publication date: 2008, then Normalized Date: 20080000

Publication date: Sep. 2009, then Normalized Date: 20090900

Publication date: Jan.-Mar. 2010, then Normalized Date: 20100300