According to the old English time system, a moment is 1 and a half minutes.
In the middle ages, an hour was considered to be made up of 40 minutes, with each minute divided into 40 moments. Disregarding the elastic notions of time then prevailing, and allowing 3,600 modern seconds to the hour, that gives us 90 seconds to each minute. These minutes would contain 40 moments of precisely 2.25 seconds each.
The word "moment" is used shockingly casually these days. Personally, if anyone says to me, "I'll be with you in half a mo'", I get impatient one and one-eighth of a second later. Yes, I did use to be a schoolteacher.