NeoCal for Palm OS User Guide
Durations
The duration conversion buttons either assign a duration unit (when the value in the x register is not already a duration) or convert a duration to another unit. The following buttons represent the duration conversions:
for years
for months
for weeks
for days
for hours
for minutes
for seconds
for frames
These conversions are determined by values stored in the following date conversion registers:
for the number of days per year (365.25)
for the number of days per month (30.4375)
for the number of days per week (7)
for the number of hours per day (24)
for the number of frames per second (30)
Just like the user registers, these registers are accessed using the 
and 
buttons. As a convenience, pressing one of these buttons while entering a number will cause any pending operation to be performed and then store that number in the register. Otherwise, pressing a date register button will recall it's value into the x register.
The 
button resets the date conversion registers to their default values, except for the register whose value is displayed as a reminder. It is important to clear the date registers before performing a series of date calculations to ensure consistent results. (The button also clears the date moment registers.)
The 
, or fractional part, button takes the fractional component of a duration and converts it to the next smaller unit.
For example,
- Press to reset the date registers.
- Press
to enter 1 year. - Press to convert to 12 months.
- Press to convert to 52.18 weeks.
- Press to convert to 365.25 days.
- Press to convert to 31,557,600 seconds.
This example shows duration converions based on a forty-hour work week,
- Press to reset the date registers.
- Press
to store 8 in the hours per day register. - Press
to store 5 in the days per week register. - Press
to enter 134 hours. - Press to convert to 3.35 weeks.
- Press to calculate 1.75 days (0.35 weeks).
- Press to calculate 6 hours (0.75 days). This shows that 130 hours is the same as 3 weeks, 1 day, and 6 hours.
Duration arithmetic can also be performed, for example:
- Press to reset the date registers.
- Press
to add 1 hour and 30 minutes to generate the result of 1.5 hours. - Press to add 1 day and 48 hours to generate the result of 3 days.
- Press
yields the result of 1.29 weeks. Pressing shows this to be 1 week and 2 days.
In addition, there are three time conversion functions:
converts hours in decimal-fraction (H.h) format to minutes-second (H.MMSSs) format.
converts hours in minutes-second format to decimal-fraction format.
converts hours in minutes-second format to frames in decimal-fraction format.
For example,
- Press
to convert 2.5 hours to 2 hours 30 minutes (2.30000). - Press to convert 4 hours 23 minutes 48 seconds to 4.3967 hours.
- Press to convert 1 minute 30 seconds to 2,700 frames (assuming 30 fps).
- Press to convert 1,000 frames to 33.3 seconds (0.00333).
