Day (d) Conversions
A day is approximately the period of time during which the Earth completes one rotation around its axis. The unit of measurement "day" is defined as 86,400 SI seconds and symbolized d. The second is designated the SI base unit of time. Previously, it was defined in terms of the orbital motion of the Earth in the year 1900, but since 1967 the second and so the day are defined by atomic electron transition.
All Day Converters
Day can be defined as each of the twenty-four-hour periods, reckoned from one midnight to the next, into which a week, month, or year is divided, and corresponding to a rotation of the earth on its axis.