A sequential time is one in which the numbers form a normal sequence, such as 1:02:03 4/5/06 (two minutes and three seconds past 1 am on 4 May 2006 (or April 5, 2006 in the United States) or the same time and date in the "06" year of any other century).
[citation needed] Other sequences, such as the decimal numbers of the mathematical constants π (3/14/1592), e (2/7/1828), and the square root of two (1/4/1421) are also noted.
Dates with repeating numbers such as July 7, 2007 "7/7/07" are also popular.
[1] Palindromic times can also be observed, e.g. 10:02:10 on 11/01/2001 (two minutes and ten seconds after 10 am on 11 January 2001 in parts of the world using month/day format) was the first fully palindromic time sequence of the twenty-first century.
The last palindromic time sequence was at 02:02:10 at 11/01/2020 (two minutes and twenty-one seconds past 2 am on 11 January 2020 in most of the world).