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Getting Started

  • On the Locate screen, pinch and scroll around on the map or use the locate arrow GPS locate arrow to have GPS find your current location. Select your city or the current GPS location from the list. The red calendar icon Red calendar icon and check mark Blue check mark icon will indicate which location you have chosen.
  • If your city is not in the list, swipe "Map Center" or one of the closest cities in the table and select "Copy to Fav". If the locate arrow is solid, tap the GPS arrow until it is hollow (which turns it off) and try swiping again. On the Favorites screen you can change the name and coordinates and then select it. The "Sun & Moon" and "Calendar" screens will use the selected location.
  • To close the tutorial guides, tap on one of them or the dismiss Red dismiss button icon button.

Sun & Moon Screen

Sun and Moon screen
  • You can swipe the center area left or right to advance or go back a day. The date (underlined with green) below the slider is also a button, tap it to select a new date.
  • The acronym in parenthesis is the name of the time zone for that day. It will help in determining if standard time or daylight saving time (DST) is in effect for that day. For example:
    ESTEastern Standard Time
    EDTEastern Daylight Time
    PSTPacific Standard Time
    PDTPacific Daylight Time
    WETWestern European Time (winter time)
    WESTWestern European Summer Time
    CETCentral European Time (winter time)
    CESTCentral European Summer Time
  • Use the slider to change the time. When either the date or time is modified, the time beside it will be shown in italics, meaning that "Track Sun & Moon" is off.
  • To turn "Track Sun & Moon" on, select the date button and choose Track Sun & Moon. You can also turn it on in the Settings screen.
  • When "Track Sun & Moon" is on, the screen will show the current date and time (i.e. the local time) for the location selected and the sun and moon positions. The sun and moon icons will 'track' or traverse the screen individually as time advances naturally, if the slider is moved, or if the is date changed. These icons show an approximate location for each body if it is above the horizon—they are not 100% astronomically accurate and although they may appear to predict eclipses, they are not intended to do so. The times in the table are accurate.

Calendar Screen

Calendar screen
  • The calendar will be generated based on the last location you selected on either the Locate or Favorites screen. The red calendar icon and check mark on those screens will indicate the location used to generate your calendar.
  • The action menu button, circled in green (above picture, lower-left area), allows you to print, email, save or copy the calendar.
    • Action menu selections
    • When you choose to Print or Email the calendar, you will be asked to select the number of months. The app will print or make the .pdf, starting with the current month on the screen, so that each month is on its own page.
    • Save Image will save the month on the screen to Photos (the Photos app, also known as the Camera Roll.)
    • Copy Image will copy the month on the screen to the clipboard.
  • To get the CSV data, turn on "Attach CSV to Email"  Toggle on/off switch for CSV data on the Settings screen, Options area. Then choose the Email action here, select the number of months desired and email it. The email will have two files attached, a Calendar.pdf for printing and a Calendar.csv file with all the data for those months.
  • You can also retrieve the files by attaching your device to a computer running iTunes. See iTunes Shared Folder. Generate the files by selecting Email (set the CSV option On if you want that file too), once the email app is shown, they are available in the shared folder. You can "Send" or choose "Delete Draft" in the email app.

Locate Screen

Locate screen
  • Scroll around and zoom in and out on the map to find the location you are interested in and tap on it in the list—you can also choose the Map Center row. It will be selected and moved to the top of the list, as this table is sorted in ascending order by distance, closest to the map center.
  • A red calendar icon Red calendar icon and check mark Blue check mark icon will be shown next to your selection designating that it will be used to make your calendar.
  • The DST texts, "DST: Y" and "DST: N", indicate if the location observes DST rules. A 'Y' means that it may change its clocks to observe DST if the rules say so—the app automatically adjusts the times for those days. Click "Visit DST page" to see the rules used by this app. A 'N' means that location will never and has never observed DST.
  • You can set a city to be a favorite—they will be shown with a Yellow star icon yellow star. Favorites will always show up in this list, sorted by distance with the other locations.

    Example: Making a Favorite
    Suppose you live near Oceanside, California and want to make it a favorite. Move the map to Oceanside.

    Locate screen centered on Oceanside

    Swipe that row (when GPS is off) and tap "Copy to Fav" to copy it to your favorites list.

    Swipe a row to copy example

    You can now leave it as a favorite, or on the Favorites screen you can rename it and edit its latitude, longitude, and time zone. Note: If you edit a predefined location you will get a copy of that location, so it is helpful to give it a new name to distinguish it from the original.

  • If the location that interests you is not in the list, center it in the map. Turn on the Reticle (a switch on the Settings screen) to help you find the center of the map. The time zone and DST of the row "Map Center" will be determined by the closest location found. Swipe the row "Map Center", select "Copy to Fav", and then edit the name and other data on the Favorites screen.

Locate Screen — GPS

  • Click the "GPS Locate Arrow" GPS locate arrow on the left side of the center bar (iPhone) or top bar (iPad) and the app will attempt to find your current location using either GPS, WiFi or cellular signals, whichever is available and most accurate.
    The three GPS modes

    The three GPS modes.

  • When your location is found, the map will be scrolled to and centered on your location and the app will keep it centered—this will be indicated by making the locate arrow solid and highlighting it with blue. Choose the row "Current GPS Location" for the times to be calculated for your current position.
  • You can scroll the map, the blue highlight will go away, but the app will still track your current location.
  • To turn off the GPS for this app, tap the Locate Arrow once or twice until the arrow is hollow. Your last GPS location will be listed in the table and a purple circle will be drawn on the map around the last known position. The circle will be sized with the approximate accuracy known and filled with:
     purplish blue    30 meters or better
     green 31 to 100 meters
     orange 101 to 167 meters
     red any less accurate reading

    Fill colors indicate accuracy.

    GPS accuracy circle

    Best accuracy (purplish-blue) example.

  • It may take up to one minute to find your location—usually it will be found within a few seconds. If your location cannot be found within 60 seconds, the request will be cancelled.
  • If the map is not available, i.e. you are out of WiFi and cellular range, you can still use the locate feature if your device has GPS and Location Services is enabled (in iOS Settings > Privacy > Location > Sun Calendar). The app will center on a blank map and the "Map Center" and "Current GPS Location" rows will have the latitude and longitude it found.
  • The reticle will not be shown when GPS in on and centered. Sometimes when it reappears it may not be exactly centered—try rotating your device around, from portrait to landscape and back, that will usually center it again.

Locate Screen — Search

  • The Search Text entry area for Search text area, or the Search icon (the magnifying glass) Magnifying glass icon for Search on the iPhone, will allow you to enter search terms. An Internet connection is required to use this feature—the search is sent to Apple servers that search their database.
  • Search terms can be:
    • City or town
    • State or 2-letter abbreviation
    • Province
    • Country name, 2-letter or 3-letter abbreviation (e.g. za, fi, jp, can)
    • U.S. zip code or other postal codes
    • Major airport codes (e.g. bru, lga, nrt, lim)
  • To help narrow your search, center and size the map onto the believed region of the location. The search will use that area first, then it will expand its search to the rest of the world.

Locate Screen — Red Pin

Red pin on the Locate screen
  • You can set the Red Pin anywhere you like—you can also choose it as your selected location. To drop a Red Pin, press-and-hold on the map where you want it. You can have only one Red Pin; it cannot be dragged, but you can change its location. Move it by doing a long-press (press-and-hold for about one second) on the new location.
  • When you drop a Red Pin it will choose the time zone and DST rule of the city closest to it.
  • It is useful to drop a pin and then scroll around on the map to measure distances from the Map Center to the Red Pin. In the picture above, the Red Pin is 0.51 miles from the center of Oceanside. If the distance is less than 1 mile or 1 nautical mile, feet will also be shown, if less than 1 kilometer, meters will be shown. These distances are approximate, but should be fairly accurate.
    Red pin and its annotation

    The pin and its annotation.

  • You can hide the Red Pin by tapping the pin, then tap the red-minus sign in the pin's annotation. You can also hide it on the Settings screen.
  • The Red Pin will not show on the Favorites map, but you can swipe the row here to copy it there.

Favorites Screen

Favorites screen
  • A new or selected location will be marked on the map with a purple pin. Other favorites (up to 50) will be shown as green pins.
  • To move the purple pin, press-and-hold on the map at the new location—don't try to drag the pin. Tap Save to save your changes.
  • To change the order of the favorites, tap the Edit button and move them around by dragging this Dragger icon for list reorder icon. Click Done when finished.
  • To delete a favorite location, swipe that row and select Delete.
  • To add a new favorite, tap the + button in the center bar (top bar on iPad). The app will create a new favorite location and pin it in the center of the map. The time zone and DST rule will be set based on a nearby city found in the database. If there is no nearby city, it will choose a time zone based on the longitude and set the DST to none. You must verify that the time zone and DST rule settings are correct (for iPhone: click the circled i to go to the Detail screen).
    Detail screen
  • Use the entry fields to enter a new name or new latitude and longitude coordinates. You can enter data using degrees, minutes, seconds or the decimal field—updates will be shown immediately in the other fields. Tap N or S, E or W to set those, respectively. Invalid entries will be highlighted in red and should be corrected before saving. Latitudes cannot be higher than 84°.
  • Tap the Time Zone button (above picture, circled in green) to select a new time zone and DST rule.
  • Modifications will be highlighted in light-yellow indicating that you need to save the changes. Click Save (above picture, circled in orange).
  • If you edit a predefined location you will get a copy of that location, so it is helpful to give it a new name to distinguish it from the original.
  • For iPhone: You can move the purple pin on the map, press-and-hold on the map at the new location. Click Save in the upper-right of the map when you want to set the new coordinates:
    Save button position
    Or, use the Detail screen to update the latitude and/or longitude. After saving on the Detail screen, tap the Back button to see the new placement of the purple pin.

Settings Screen

  • The optional field "Default Email" is not transmitted to any server on the Internet—it will be used to fill in the 'To:' address in the standard Apple iOS email program. It is only used as a default when you choose to email your calendars. See the Privacy Policy page.
  • When turning on "Larger Font Size on Calendar", don't select too many options or the app will be forced to make the font size small in order to fit all the text in the box. Some labels will be abbreviated, such as Moonrise will be abbreviated to Mrise, to allow for a very large font size. You should also choose a short time format, either 24-hour or "a/p, no space".


  • Accuracy
    • Sunrise & Sunset: The algorithms take the sun's diameter and Earth's normal atmospheric refraction into account and are accurate to about a second. The seconds of the actual event may be different due to varying conditions in the atmosphere that affect refraction: the amount of water vapor, the temperature of the atmosphere, the atmospheric pressure, and much smaller factors such as the presence and amount dust in the air.
    • Moonrise & Moonset: The formulas used are accurate to a minute of the actual time of the event.
    • Distance between two points: The app uses a formula that is quite accurate—generally the maximum error is ±0.3% of the distance.
  • Acronyms and Abbreviations
    • DST is Daylight Saving Time, which is called Summer Time in some regions.
    • UTC is Coordinated Universal Time. For the purposes of this app, UTC is synonymous with GMT (Greenwich Mean Time).
    • CSV is comma-separated values. It is used for importing data into spreadsheets, databases or other apps that can read tabular data.
    • N.P. is National Park
    • V.C. is Visitor Center
    • NHS is National Historic Site
    • AFB is Air Force Base
    • Co. is County. Usually in Ireland, such as Co. Dublin.
  • Sunrise & Sunset Azimuth: Azimuth is the number of degrees to turn clockwise from facing north. For example, a sunrise azimuth of 45° would rise on the horizon to the northeast. A sunset azimuth of 270° would set directly west.
  • Midnight will be displayed as 12:00m, 12:00 M, 12:00:00m, 12:00:00 M. Similarly, noon will use the same convention, using N: 12:00n, 12:00 N, 12:00:00n, 12:00:00 N. In case these show up, interpret 12:00 AM & 12:00:00 AM as midnight, and 12:00 PM & 12:00:00 PM as noon.
  • Dawn & Dusk are the names used in this app for civil twilight.
  • Twi Astro, Twi A (astronomical twilight) and Twi Naut, Twi N (nautical twilight) are two different levels of darkness before dawn and after dusk. The levels of darkness are defined by how far the sun is below the horizon: 6°, 12°, and 18°; respectively, dawn/dusk, nautical twilight, and astronomical twilight.
  • This app supports the years from 1901 to 2099. The Daylight Saving rules have been researched from about the year 1990 to the present. Tap "Visit DST page" below for current regions supported and their start and end dates. We will update the app with new rules when the rules change on the web site.
  • Latitudes are supported up to 84° N and 84° S. Use the website SunriseSunset.com to make a calendar with higher latitudes. You may find it more interesting to use these two predefined locations:
    • "Alert, Nunavut, Canada" at 82° 31' N, 62° 19' W
    • "McMurdo Station, Antarctica" at 77° 51' S, 166° 40' E
  • When a location needs a time zone and it is in the open ocean or not near a predefined city, the time zone will be determined by this formula: the integer portion of (longitude divided by 15°). For example, a new favorite at 159° east will have the time zone UTC +10:00 and the DST rule set to none.
  • When GPS is on, you cannot swipe a row to make it a favorite because the GPS constantly sends location updates to the app. For each new GPS location the app has to calculate all the distances to the map center, sort them and refresh the nearby locations table.
  • CSV File Specifications
    CSV sample

    Partial sample of CSV data.

    List of data returned in the .csv file. Each row will be a day; the columns will contain:

    • Date
    • DST in effect: true/false
    • Sunrise1
    • Solar Noon2
    • Sunset1
    • Moonrise2
    • Moonset2
    • New Moon2 3
    • First Quarter Moon2 3
    • Full Moon2 3
    • Last Quarter Moon2 3
    • Civil Dawn1
    • Civil Dusk1
    • Nautical Dawn1
    • Nautical Dusk1
    • Astronomical Dawn1
    • Astronomical Dusk1
    • Sunrise Azimuth2
    • Sunset Azimuth2
    • Moonrise [%] Illuminated2
    • Moonset [%] Illuminated2
    • Moon Noon [%] Illuminated3
    1. If that event does not occur on that date, the field will contain 'light' or 'dark' indicating if the sun is up or down.
    2. Field will be blank if that event does not occur on that date.
    3. The moon's phase and percent illuminated will be calculated even if the moon is not above the horizon; these events do not depend on the viewer's location.

iTunes Shared Folder

This app uses a shared folder on this iPhone, iPad or iPod Touch that is accessible from a computer running the iTunes application. This folder stores the Calendar.pdf, Calendar.csv and log files. To access these files:

  • Attach your device to a computer running iTunes.
  • Select your device in the iTunes interface.
  • From the Settings list under your device select Apps. The right pane will fill with the apps that are installed on your device.
    iTunes settings list

    iTunes settings area, Apps selected.

  • Scroll down in the entire right pane (not just the Apps list). Under the Apps list section find the File Sharing section. NOTE: This section may take a few seconds to load—keep scrolling down until you see it. This lists all the apps that are allowed to share files on that device.
    File sharing apps

    File Sharing Apps section.

  • Click on Sun Calendar in this app list and you will see the files available.
    Shared documents

    Files in shared folder.

  • Use the "Save to..." button to transfer any of the files to your computer.

You can add files to this folder, but please don't—the app is not expecting any new files there. You can delete any of these files (the app will recreate them as needed), but it is not recommended. You may delete the file ESEAbortLog.txt if the app keeps asking you to delete it. Email support for more information.


  • For information on books, video lectures, graphics, etc., that were used, please visit the Support Website.

Copyright © 2017 Steve Edwards
All rights reserved.