The publication date for each book and set are inserted automatically, based on the most recent change to an SGML source file for that particular book. The latestdate.sh script reads the doc/i/* source directory for every book, extracts the date of the most recently updated file, and creates an entity file with the publication dates for all the books, similar to this:

<!-- Latest Dates -->
<!entity api-date " Jan 31, 2003 ">
<!entity cc-date " Jan 09, 2003 ">
<!entity dh-date " Jan 15, 2003 ">
<!entity gm-date " Jan 22, 2003 ">
<!entity gl-date " Jan 27, 2003 ">
<!entity gg-date " Jan 27, 2003 ">
<!entity gp-date " Jan 23, 2003 ">
<!entity gq-date " Jan 23, 2003 ">
<!entity hi-date " Jan 22, 2003 ">
<!entity p1-date " Jan 08, 2003 ">
<!entity p2-date " Oct 05, 2001 ">
<!entity p3-date " Jan 08, 2003 ">
<!entity p4-date " Jan 16, 2003 ">
<!entity p5-date " Jan 08, 2003 ">
<!entity p6-date " Jan 08, 2003 ">
<!entity sr-date " Dec 11, 2002 ">
<!entity drcf-date " Jan 31, 2003 ">
<!entity drdn-date " Jan 31, 2003 ">
<!entity drpb-date " Jan 31, 2003 ">
<!entity drgn-date " Jan 31, 2003 ">
<!entity drmb-date " Jan 30, 2003 ">
<!entity drsd-date " Jan 30, 2003 ">
<!entity tst-date " Jan 15, 2003 ">
<!entity tl-date " Jan 22, 2003 ">
<!entity tu-date " Jan 27, 2003 ">
<!entity pd-date " Jan 31, 2003 ">
<!entity wp-date " Jan 16, 2003 ">
<!entity today-date " January 31, 2003 ">

This file is named dates.sgml and is included as the entity "datefile" in the doc/i/common/entities.sgml file.