calc: HMS Forms
5.8 HMS Forms
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“HMS” stands for Hours-Minutes-Seconds; when used as an angular
argument, the interpretation is Degrees-Minutes-Seconds. All functions
that operate on angles accept HMS forms. These are interpreted as
degrees regardless of the current angular mode. It is also possible to
use HMS as the angular mode so that calculated angles are expressed in
degrees, minutes, and seconds.
The default format for HMS values is ‘HOURS@ MINS' SECS"’. During
entry, the letters ‘h’ (for “hours”) or ‘o’ (approximating the “degrees”
symbol) are accepted as well as ‘@’, ‘m’ is accepted in place of ‘'’,
and ‘s’ is accepted in place of ‘"’. The HOURS value is an integer (or
integer-valued float). The MINS value is an integer or integer-valued
float between 0 and 59. The SECS value is a real number between 0
(inclusive) and 60 (exclusive). A positive HMS form is interpreted as
HOURS + MINS/60 + SECS/3600. A negative HMS form is interpreted as -
HOURS - MINS/60 - SECS/3600. Display format for HMS forms is quite
flexible. 
HMS Formats.
HMS forms can be added and subtracted. When they are added to
numbers, the numbers are interpreted according to the current angular
mode. HMS forms can also be multiplied and divided by real numbers.
Dividing two HMS forms produces a real-valued ratio of the two angles.
Just for kicks, ‘M-x calc-time’ pushes the current time of day on the
stack as an HMS form.
Info Catalog
calc: Strings
calc: Data Types
calc: Date Forms