About SolTemp

Sol (solar) + Temp (temporal) = SolTemp!

The Solar Temporal Dashboard (SolTemp) is an interactive web map that visualizes sunrise times, sunset times, day length, solar noon, and time-zone offsets across the northwest quadrant of the globe - with regional variations covering southern Asia and Oceania being developed. Beyond showing raw solar data, SolTemp lets you explore how different time-zone policy proposals — from permanent daylight savings time to full true-solar-time alignment — would change the clock times of sunrise and sunset for any location on the map.

Time Policy Opinion Poll

Have an opinion on which time-policy scenario works best? Share it at: soltemp.info/poll

Poll results are available to the public, and displayed at soltemp.info/poll/results

About the developer

Kyle Kasparek — Portfolio | LinkedIn

I'm a GIS professional based in the Pacific Northwest. An alumni of Central Washington University, I hold a Bachelor of Science alongside a GIS certificate, and have two years of professional work experience in local government managing the internal and public-facing GIS system for the public works department at Franklin County (WA), where I gained experience building online web and field map applications through Esri's ArcGIS Suite. My primary interests in the GIS sector are web application development, cartography and solving problems using spatial analysis workflows.

The Clock Change Debate

Every year, across much of the world, clocks are adjusted forward by one hour in spring ("spring forward") and back again in autumn ("fall back") — a system known as Daylight Savings Time (DST). In the United States and Canada, most areas spring forward on the second Sunday in March and fall back on the first Sunday in November; in Europe, most spring forward on the last Sunday in March and back on the last Sunday in October. Southern Hemisphere nations such as Australia, New Zealand, and Chile have their own spring forward and fall back dates.

These clock changes shift the timing of daylight relative to daily schedules, producing lighter evenings and darker mornings while DST is in effect, compared to standard time. While intended to make better use of daylight, the practice has also been associated with disruptions to sleep patterns, safety concerns, and broader questions about how closely clock time should align with the sun. These trade-offs form the basis of the modern clock change debate.

In recent years, that debate has intensified. Polling in both the United States and Canada suggests that a majority of people — along with many policymakers — support ending these biannual clock changes. However, there is no clear consensus on what should replace them. In the United States, opinion is roughly evenly split between permanent DST and permanent standard time, with a significant share of respondents expressing no strong preference, and a small share expressing support for continuing the status quo. Political positions are similarly divided, though recent federal and state-level efforts have tended to favour permanent DST — examples being the Senate's 2023 passage of the Sunshine Protection Act and various state laws that would adopt year-round DST pending Congressional approval.

Canada follows a different framework, where time zones are set at the provincial and territorial level. This has allowed some jurisdictions to act independently: Saskatchewan has observed Central Standard Time year-round since the 1990s, while Yukon (2020) and British Columbia (2026) have adopted a fixed UTC−7 offset, effectively making Daylight Savings Time permanent. Some smaller regions, including portions of Western Ontario and Eastern Quebec, have chosen to adopt permanent standard time instead. Other provinces have considered similar measures.

Now, how could I use spatial analysis to resolve the time change debate? That question became a focus upon graduation from CWU, and I spent some time in early 2022 producing a QGIS prototype that mapped sunrise and sunset across the United States as raster layers with the intent of creating a series of print layout maps — the initial concept behind what would later become SolTemp. Professional commitments delayed further development, but the idea remained.

Building SolTemp

After leaving Franklin County, I decoded to use my free time to return to the concept. With a foundation in HTML, CSS, and JavaScript in addition to my GIS experience, I began using AI-assisted development tools to build an interactive web map — a format better suited to communicating these spatial patterns than static outputs. I launched SolTemp in the fall of 2025, alongside a Story Map — Solving Time: A spatial perspective on the clock change debate — which presents the background and findings in narrative form, and presented the project at the 2025 Northwest GIS Users Conference in Boise, Idaho. The goal remains consistent with the original prototype: to make the effects of time-zone policy alternatives tangible, and to let the maps speak for themselves.

Since the conference, I have been spending time perfecting my original westward shift solution, using grid models in QGIS to help determine the best time zone boundaries across the Lower 48.

What the map shows

SolTemp covers the northwest quadrant of the globe — from 0 (the equator) to 85 degrees North latitude, and from 0 (the prime meridian) to 180 degrees West (the antemeridian) longitude, covering North America, Central America, the Caribbean, the northern part of South America and far-eastern Siberia. I have created other variations covering South Asia (from Iran to Japan - 0 to 55 N latitude; 44 to 150 E longitude) and Oceania (Australia, New Zealand and portions of the South Pacific - 0 to 55 S latitude; 90 E to 120 W longitude). Each region can be coloured by any of five modes — Sunrise, Sunset, Day Length, Solar Noon, and Time Zone — making it easy to see regional patterns at a glance for any date between 2024 and 2050.

The Sunrise and Sunset modes use a warm colour gradient that reflects the time of day: Sunrise runs from 23:00 (white) through cyan, green, yellow, orange, red, and purple to near-black at 15:00. Sunset uses the same colours in reverse, from 11:00 through to 03:00. Day Length shows total daylight from polar night (deep purple, 0 h) through teal and green to pale yellow at 24 h.

Solar Noon maps how close the local clock noon is to true astronomical noon. The gradient runs across five zones: 08:00–10:30 is deep blue through cyan to green (solar noon very early — clock runs well ahead of the sun); 10:30–11:30 transitions from green to yellow; 11:30–12:30 passes through pale yellow, with the brightest near-white point at exactly 12:00 (perfect alignment); 12:30–13:30 transitions from yellow to orange; and 13:30–16:00 deepens from orange through brown to dark red (solar noon very late — clock runs well behind the sun).

Time Zone shows the UTC offset in effect at each location under the selected time-policy scenario.

Clicking any location opens a solar analysis panel showing that point’s sunrise, sunset, and day length, along with a full altitude and azimuth chart for the sun throughout the chosen day. Named city markers can be toggled on to display sunrise and sunset times directly on the map. Most distinctively, SolTemp lets you switch between multiple time-zone policy scenarios (up to sixteen for North America) and see instantly how each proposal would affect every location on the map.

How to use SolTemp

Choosing a display mode

The five buttons at the top centre of the map switch between display modes. On desktop they are always visible; on mobile, tap the gear icon (⚙) to reveal the controls panel. The active mode is highlighted in blue.

• Sunrise — colours the map by local clock time of sunrise. Useful for seeing how early or late the sun rises across different time zones and latitudes.
• Sunset — colours the map by local clock time of sunset.
• Day Length — colours the map by total hours of daylight. Highlights polar day and polar night regions at extreme dates.
• Solar Noon — colours the map by local clock time of solar noon, using a five-zone gradient: deep blue at 08:00 (solar noon very early) through cyan and green, brightening to near-white yellow at 12:00 (perfect alignment), then warming through orange and brown to dark red at 16:00 (solar noon very late). The pale yellow zone between 11:30 and 12:30 shows locations where the clock is closest to true solar time.
• Time Zone — shows the UTC offset in effect under the selected time-policy scenario. Switch scenarios to compare how different policies redraw the map.

Selecting a date

Reading the hover tooltip

On desktop, move the mouse over any part of the map to see an information box in the lower-left corner. It shows:

• The coordinates and UTC offset of the hovered point.
• Sunrise, solar noon, and sunset times in local clock time.
• Total day length in hours and minutes.

Clicking a location

City markers and labels

The label-mode control in the top-right corner of the map has three settings:

• None (default) — no city markers. Best for browsing the colour gradient without clutter.
• Markers only — small dots mark city locations. Hover a dot to see a pop-up badge with that city’s sunrise and sunset times. (Desktop only.)
• Markers + labels — city badges showing name, UTC offset, and sunrise/sunset times are displayed directly on the map, with automatic collision avoidance so they don’t overlap.

Clicking a city dot or badge opens that city in the analysis panel.

Time-policy scenarios

Search, share, and the home button

The search bar in the top-right of the map accepts place names and raw decimal coordinates (e.g. 47.6, -122.3). A successful search moves the view to that location and opens the analysis panel for it.

The share button (🔗 link icon, below the search bar) copies a direct link to the current location and zoom level to your clipboard. The link takes the form https://soltemp.info/#coord=LAT,LNG&zoom=Z and can be pasted anywhere. Opening a share link automatically centres the map, sets the zoom, and opens the analysis panel for that location — exactly as if you had clicked it yourself. Share links pointing to coordinates outside the map’s coverage area (eastern hemisphere, southern hemisphere, or above 85°N) redirect to the main page.

The home button (⌂) below the zoom controls resets the map to the default view for that region.

Mobile usage

On smaller screens, the map fills the full viewport. The controls panel is hidden by default and revealed by the gear button (⚙) near the top-left of the map. The analysis panel slides in from the right when you tap the ◀ button on the right edge, and slides out again when you tap ▶. The time-policy scenarios dropdown is revealed by the Tap to View Time Zones button near the bottom-left.