TimeCalc v1.6

by Tom Woods

 

email: tom.woods@lasp.colorado.edu
 



Table of Contents

Overview
Contents of the Zip File
System Requirements
Installing/Upgrading
Uninstalling
Instructions

TimeCalc Display
Preferences
Time Conversions
Time Tools
Stop Watch
Timer
Alarm
Contact Time

Future Enhancements
Bug Reporting
Disclaimer
Versions
Remarks / Known Bugs


1. Overview

TimeCalc is a PalmOS application that converts date and time to a variety of time standards: Julian Date, Day of Year, and Seconds of Day. TimeCalc also has some user options for defining special dates and different time zones. The primary reference time is Universal Time (UT, also known as GMT). The user options for dates specify the number of days since a given date and is useful for tracking days of a mission, such as the NASA UARS and TIMED satellites that are the default preferences. The user options for times permits the display of the time in two other time zones besides the primary UT display and is useful for displaying local time.

The TimeCalc version 1.6 allows the 3 User Times to be either Time Zone Clocks (e.g., EST) or Second Counters (e.g., GPS).

The TimeCalc version 1.5 includes an option to load the contact times from a Memo record, an option to display fraction of day for the dates, and color icons for the time tools.

The TimeCalc version 1.4 uses the System Preference of the date format for displaying the date, such as M/D/Y or D-M-Y. The user can select this date format using the standard Palm OS Pref application.

TimeCalc, version 1.3 or later, also has an user option to display a second counter relative to a given date such as for GPS or UNIX time.

TimeCalc, version 1.2 or later, also includes several time tools: a stopwatch, a up/down timer, an alarm, and a satellite contact time alarm. For the contact time, the user can set the times for the contact along with alarm options, and then TimeCalc graphically displays the time until the contact begins.


2. Contents of the Zip File

The following files are included in the zipped file: TimeCalc.zip

- TimeCalc.prc (The PalmOS program)
- TimeCalc.htm (This help file)
- *.jpg (graphics for this file that are located in the Images folder)


3. System Requirements

- PalmOS v3.0 or above


4. Installing/Upgrading

First time installation
- To install this program, use your Palm device install tool and Hotsync to load the file: TimeCalc.prc (after you unzipped it from the Zip file) into the Palm device.

Upgrading - To upgrade to a newer version and keep your settings, DO NOT remove the application from your Palm device. Install only the TimeCalc.prc file. You can check / reset the settings using the TimeCalc Preference menu item.


5. Uninstalling

To uninstall, simply delete the application from your device using the "Applications Manager".


6. Instructions

This section gives instructions on using the TimeCalc (Time Calculator) application.





The TimeCalc menus, as shown, has three choices in the Options menu and five choices in the TimeTools menu. These options are discussed in the following sections.


6.1 TimeCalc Display

- The top 2 fields give the date and time in Universal Time (UT, also known as GMT). The date is given in the Month/Day/Year format, and the time is given in Hour:Minute:Second format.
- The DOY field is the Day Of Year with DOY being 1 on Jan. 1.
- The JD field is the Julian Date, started by Julius Caesar in 45 BC, and is the number of days since noon Jan. 1, 4713 BC (the time that ancient Romans thought history began). Because TimeCalc gives the JD value at 0 UT, each JD value has a fractional value of 0.5.
- The SOD field is the Seconds Of Day for the UT time.
- The GPS field is the Global Positioning Satellite time, which is the seconds since Jan. 6, 1980 0 UT. Prior to Version 1.2, the GPS time included an estimate of leap seconds. As of Version 1.2, the leap seconds are not added to the GPS time value. As of Version 1.3, this GPS time is user defined to be a second counter based on any start date.
- The other 4 fields are user specified options for dates and times. Setting these options is described in the Preferences section of the manual.
- The user options for dates specify the number of days since a given date and is useful for tracking days of a mission, such as the NASA UARS and TIMED satellites that are the default preferences.
- The user options for times permits the display of the time in two other time zones besides the primary UT display and is useful for displaying local time.
- The bottom panel displays the active time tool. For this display, the stop watch is shown.

6.2 Preferences

- The TimeCalc preferences are accessible through the menu. Selecting the menu Preferences item brings up the TimeCalc Date or Time Preferences dialog.
- The Date Preferences dialog includes the options for the user dates. One needs to specify a name and date for each of the 2 user dates. The name will be truncated to fit within the allowed space on the main TimeCalc display, so you will need to keep the name short. The date value is day zero; that is, the TimeCalc main display will list the number of days since this day zero. For some NASA missions the launch day is mission day 1, thus the day zero value needs to be specified as the day before launch. For other NASA satellites the mission day is days since launch, thus the day zero value needs to be specified as the day of launch.
- There is an option in the Date Preferences dialog to display the time as a fractional day with the Day Of Year (DOY) value. If activated, then the time (H:M:S) is included as a fraction of day in the DOY value. Otherwise, the DOY value is just displayed as an integer value.
- The "UT to Palm (hr)" field in the Time Preferences dialog is the number of hours between your PalmOS system time and the UT (GMT) time. For the Eastern Time zone, this value is -5 hours during standard time (EST) and is -4 hours during daylight savings time (EDT). It is important to specify this value correctly as the two user time zone options rely on this value too.
- The bottom section in the Time Preferences dialog includes the options for the user times. One needs to specify a name and time offset for each of the 2 user times zones. The time offset is the number of hours from the reference UT (GMT) time. For the Eastern Standard Time (EST) zone, this offset is -5 hours (note the negative sign).

6.3 Time Conversions

TimeCalc has two modes for time conversions: the NOW mode and the CONVERT mode.

The NOW mode displays the current time and is updated once a second for all fields. The NOW mode can be started by clicking on the Now button.

The CONVERT mode displays a single conversion and does not update the time continuously. Clicking on any of the fields or the Pick Date or Pick Time buttons will put TimeCalc into this CONVERT mode. When you click on one of the fields, the Input dialog will appear and allow you to enter the new value for that field. Then TimeCalc will update the values for the other date and time fields with this new input.

The following are the dialogs for the Pick Date, Pick Time, and Input for User Time (GPS time). The Pick Date and Pick Time dialogs are the standard PalmOS Version 3 dialogs for selecting a day and the time, respectively.


6.4 Time Tools

New for TimeCalc Version 1.2 are the Time Tools: Stop Watch, Up/Down Timer, Alarm, and Satellite Contact Time Alarm.
- The Time Tools are displayed in the bottom panel of the TimeCalc form.
- The Time Tools work regardless if TimeCalc is in the NOW or CONVERT mode. So you can continue doing time conversions while a Time Tool operates.
- The Time Tools can be run in the background while you work with other PalmOS applications.
- Only one Time Tool can be operated at a time; therefore, switching to a different Time Tool will turn off the previous Time Tool operation.

The Time Tools are described in the following sections.

6.4.1 Stop Watch

- The Stop Watch displays the time elapsed in Hours : Minutes : Seconds format.
- The Start button activates the Stop Watch.
- The Stop button (same position as the Start button) halts the Stop Watch timer, but does not clear the time. One can restart the timer by clicking on the Start button again.
- The Reset button clears (sets to zero) the Stop Watch time.
- The Stop Watch icon changes while the Stop Watch is actively counting.
- There are no alarms associated with the Stop Watch.

6.4.2 Timer

- The Timer displays the time in Hours : Minutes : Seconds format.
- The Timer can be an Up Timer or Down Timer depending on your choice from the TimeTool menu. The Up Timer counts from zero up to the desired time. The Down Timer counts from the desired time down to zero.
- Before starting the Timer, one can edit the Timer value by clicking on the Timer field (the HH:MM:SS value) and entering the new Timer value in the Input dialog.



- The Start button, shown in the above Timer display, activates the Timer.
- The Stop button (same position as the Start button) halts the Timer, but does not clear the time. One can restart the timer by clicking on the Start button again.
- The Reset button clears (sets to zero) the Time - this resets back to zero for the Up Timer or to Timer total time for the Down Timer.
- The Timer icon changes while the Timer is active. There is also a status bar that fills up based on the time left on the Timer. This status bar is half full when the timer has completed half of its allotted time.
- An alarm will sound when the Timer finishes, or whenever the Stop button is pressed.

6.4.3 Alarm

- The Alarm displays the alarm time in Hours : Minutes : Seconds format.
- Before turning on the Alarm, one can edit the Alarm time by clicking on the Alarm field (the HH:MM:SS value) and entering the new Alarm time in UT (GMT time zone) in the Input dialog.
- The On button activates the Alarm.
- The Off button (same position as the On button) turns off the Alarm.
- The Alarm icon has a different look depending on if the Alarm is on or off. For 30 seconds after a alarm goes off, the Alarm icon will blink.
- An alarm will sound when the Alarm finishes, or whenever the Off button is pressed.

6.4.4 Contact Time

- As of TimeCalc version 1.1, a satellite contact alarm option is available from the TimeCalc menu. A contact is the time during which communication to a satellite occurs. For satellites in low-Earth orbit, the communication time to a ground station is only about 10 minutes and can occur several times per day. This enhancement to TimeCalc is to aid in supporting these contacts.
- Once the Contact Time dialog is opened, one sets the Acquisition of Signal (AOS) and Loss of Signal (LOS) times for the contact.
- One can also set alarms as the number of seconds before the AOS or LOS time. With the alarm set, the PalmOS will wake up TimeCalc when the alarm goes off and will play the standard PalmOS alarm sound.

- Once the contact times have been set, the TimeCalc display will show in its bottom panel the time until the AOS in HH:MM:SS format.
- A status bar is also displayed that counts down the last 10 minutes before the contact begins (AOS).
- The contact time works regardless if TimeCalc is in the NOW or CONVERT mode. So you can continue doing time conversions while the contact timer is operating.


- Once the contact has begun, the contact display changes to the time until the end of the contact (LOS), also in HH:MM:SS format, and the "LOS" label blinks.
- The status bar for LOS time is the percent time of the contact left.




- Once the contact ends, the contact status bar is cleared and the "End" message is displayed.
- To end a contact display early, select the menu Contact Time item to open the Contact Time dialog and then select the Cancel button.




- As of Version 1.5 of TimeCalc, one can load a list of contact times from a Memo record. The structurethat for the Memo record is the first line is the title of the Memo record and that each following line is a contact record. The format for each contact record (one line of data) is Date AOS_Time LOS_Time Message. The Date is optional and is expected to be in YYYYDOY, YYYY-DOY, or the user-defined date format (e.g., M/D/Y). The AOS_Time and LOS_Time are expected to be in H:M:S format. The Message is optional and is text that will be displayed at the top of the display while that contact is active.
- Once a contact list is loaded, TimeCalc will process each contact until the end of the Memo record is reached.
- While a contact list is being processed, one can still enter a new contact manually using the Contact Time menu item. After this additional contact is executed, the contacts from the loaded contact list will continue.
- To terminate the processing of a contact list, open the Contact Time menu item and select the Cancel button in the Contact Time dialog.


7. Possible Future Enhancements

- Update to support PalmOS Version 4.0, which explicitly includes time zones.


8. Bug Reporting

If you find a bug or want to suggest an enhancement, send e-mail to tom.woods@lasp.colorado.edu


9. Disclaimer

This product is provided without any warranty and the user accepts full responsibility for any damages, consequential or otherwise, resulting from its use.

This archive is freely redistributable, provided it is made available only in its complete, unmodified form with no additional files.


10. Version History

 Version

Release Date

Changes
 Ver 1.6.1  Mar. 20, 2004
Updated user second counter to allow for leap seconds in the time offset field in the time preference dialog.
 Ver 1.6  Mar. 6, 2004
Changed the 3 User Times to be either Time Zone Clocks or Second Counters. Also improved contact list (memo) reading and number input dialogs.
 Ver 1.5.1  Feb. 12, 2004
Fixed Day of Year bug for leap years.
 Ver 1.5  Jan. 20, 2003
Added color icons for the time tools, added option to load contact list from a Memo record, and added option to display fractional day with the dates
 Ver 1.4  Dec. 6, 2002
Changed the display of the date to use the date format specified by the user in the System Preferences (PREF application)
 Ver 1.3  Sept. 9, 2002
Changed GPS Time to have an user defined start date. Changed startup of TimeCalc so that NOW or CONVERT mode is preserved.
 Ver 1.2  Jan. 16, 2002
Added Time Tools to TimeCalc: Stop Watch, Up/Down Timer, and Alarm, along with the Contact Time alarm option from Version 1.1. The TimeCalc display and menu are restructured to accommodate the Time Tools. The leap seconds are no longer added to the GPS time.
 Ver 1.1  Jan. 3, 2002
Added Contact Time option to TimeCalc. Added tips for the dialogs.
 Ver 1.0.1  Jan. 1, 2002
Bug fix: Version 1.0.1 now allows negative time zone offset in the Preference dialog.
 Ver 1.0  Dec. 28, 2001
First release


11. Remarks / Known Bugs

- TimeCalc's time is only as accurate as the system time of the PalmOS, so you may need to update your system time occasionally to keep the time accurate. The system time is accessible using the standard Palm OS Prefs application.
- TimeCalc's precision for the Time Tools is about 1 second.
- TimeCalc is freeware. Use it if you like it. Share it with others if you want.
- No known bugs upon release of Version 1.6.


End of TimeCalc Manual