[1] Common Lispと時間とタイムゾーン - octahedron (2019-04-25 10:30:59 +09:00) http://octahedron.hatenablog.jp/entry/2018/12/04/000031

[2] Universal time と協定世界時(UTC) : セマンティックウェブ・ダイアリー (2019-04-25 10:36:21 +09:00) http://blog.livedoor.jp/s-koide/archives/2268050.html

[3] LOCAL-TIME :: A Common Lisp Library for Times and Dates (2014-12-05 11:24:51 +09:00) https://common-lisp.net/project/local-time/

[4] Erik Naggum — A Long, Painful History of Time (Erik Naggum著, 2009-05-01 13:51:31 +09:00) http://naggum.no/lugm-time.html