All buttons display a tooltip with more information on mouse hover.
Location Input
Enter a zip code, city, state, country, or latitude and longitude individually or in combination. The site will look up the closest matching point and set the pin on the map. All displayed data is calculated for the location shown. The dropdown list keeps a history of previous locations; each can be kept for future selection or deleted.
Top Row Controls
The top row buttons turn green when clicked to show they are selected.
The eye button restricts solar eclipses, lunar eclipses, and moon phases to be location-specific, only showing eclipses visible from and moon phases when the moon is above the horizon at the selected location.
Eclipse Navigation
The half-shaded sun and moon buttons jump to the next or previous solar or lunar eclipse depending on the play direction. If both buttons are clicked quickly (within one second), they combine and will advance through both types of eclipses chronologically. Click again within one second to uncombine.
Moon Phase Navigation
The moon phase button shows the icon of the next or previous phase depending on the play direction. Clicking jumps to that exact date and time with all correct data displayed.
Time Adjustment
The time buttons (1h, 3h, 6h, 12h, 24h, 1w, 1m, 1y) advance by that amount. In step mode (yellow play button), they step once in the play direction. With no play button active, clicking a time button activates forward step mode automatically.
Play Mode
The forward and reverse play buttons have three states:
1st click — Step mode (yellow): Sets the direction (forward or backward) for time, eclipse, and moon phase buttons. Each click of those buttons steps once in that direction.
2nd click — Continuous play (green): Auto-advances whichever button is currently selected — time, eclipse, or moon phase.
3rd click — Off: Stops play and returns to default.
Clicking the opposite play button while one is active switches direction and enters step mode for the new direction.
If one or combined eclipses are selected, play advances through start, peak, and end of each eclipse before jumping to the next.
If a moon phase is selected, play jumps to each successive phase in the chosen direction.
Clock and Live Mode
The clock shows the current time at the set location. Clicking the clock resets the date and time to now and clears any selection.
The live button enables live updates as long as the page is active. When you return to the tab, it immediately refreshes. The title bar shows "LIVE" in green with an ECG heartbeat icon.
Date/Time Display (Green Box)
The green current display box shows either the current time (if the clock was clicked) or the date and time you've navigated to. If the date and time are current, they appear shaded and bordered. Clicking the date or time opens a calendar or clock for manual adjustment.
Solstice Comparison Boxes
The three boxes (orange for summer solstice, green for current, and blue for winter solstice) share the same Rise/Noon/Set and Show functions. (ST/DST works differently — the green row controls it and the solstice rows follow; see Standard Time and Daylight Saving Time.) The terminator lines of matching colors on the map show daylight and nighttime boundaries. Summer and winter are fixed to show the extremes.
The horizontal lines at the location show the differences in daylight length between solstices and current. The outer lines show the difference between current and the maximum/minimum.
Sunrise, Noon, and Sunset
The rise, noon, and set buttons show when these occur at the location. Clicking jumps the map to that time. Note: noon represents solar noon (when the sun is directly overhead) which may not be 12:00 on the clock.
Day and Night Length
The info boxes show the duration of day and night at the location for that date.
Standard Time and Daylight Saving Time
On the current (green) row, ST and DST choose whether displayed times use standard or daylight saving time. A single 🔒 lock icon next to the date (dimmed with a red "no" slash when off, bright when on) keeps the shown setting on all year while you play through the dates, instead of letting it auto-switch at the daylight-saving change. Click it again to return to following the date. Click ST or DST any time to switch which is shown; that keeps the current lock state.
The Summer and Winter rows show ST/DST as read-only indicators (a filled circle marks the active one). They follow the green row: with the green lock off they show each solstice's natural setting (summer = DST, winter = ST = reality); with the green lock on they all switch to that one convention, so you can compare year-round permanent-ST vs permanent-DST at the seasonal extremes. The date and ▲/▼ arrow next to each row show when that location actually switches.
Unchecking the Show checkbox removes that color's terminator line from the map.
When you play across a daylight-saving change, the map (sun, moon, planets, trails, and terminator) advances smoothly — the sun's real position doesn't jump, because DST is only a relabeling of the clock. It's the displayed clock that absorbs the shift: it falls back or springs forward by an hour at the changeover.
Map Interaction
Clicking on the map changes all displayed data to the closest location found, or shows latitude and longitude if no location matches.
The sun and moon markers on the map show their real-time positions overhead on Earth. The moon displays its current phase emoji. During active eclipses, the map shows eclipse shadows: an elliptical shadow for solar eclipses and a reddish tint on the moon for lunar eclipses.
Map Controls
Pan controls and zoom in/out buttons are provided. The center button resets both pan and zoom to default. Horizontal and vertical scales show approximate distance in miles. The mouse wheel can also zoom in and out.
