On Sunday, June 26, 2011 12:57:15 pm hernan gonzalez wrote: > > An instant is a point in the universal time, it's a physical concept, > unrelated to world calendars. The time point at which the man first landed > on the moon is an instant, as is the moment at which my server restarted. > It is not related to a Timezone at all. We can specified it by some > arbitrary convention (milliseconds passed since the first atomic explosion > at Hiroshima), or by some human calendar at some place/moment: for > example, the "wall date and clock used at New York". If (only if) you use > a Gregorian Calendar to specify/show a instant, you need a date, a time > and a timezone. (but you have many timezones to choose from - as you have > several calendars - a timezone is not determined by an instant). A full > datetime (date, time, timezone) implies an instant - but an instant does > not imply a timezone. You might want to review the Theories of Relativity, which pretty much blew away the notion of an absolute time and introduced the notion of frame of reference for time. -- Adrian Klaver adrian.klaver@xxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
