astronomical day

In the Conference at Rome the universal day was made to coincide with the astronomical day.

The astronomical day commences at noon of the civil day of the same date.

We may remark that the commencement of the astronomical day commences twelve hours after the civil day.

The astronomical day is reckoned from noon to noon, continuously through the twenty-four hours, like the other days.

The astronomical day based on the sun, is 24 hours long, as said before.