NOTE 1 On a time scale consisting of successive steps, two distinct instants may be expressed by the same date (see Note 1 of the term "time scale" in 113-01-11).

NOTE 2 With respect to the specified time scale, a date may also be considered as the duration between the origin of the time scale and the considered instant.

NOTE 3 In common language, the term “date” is mainly used when the time scale is a calendar as a sequence of days.