HikeSpan
HikeSpan · Daylight

Finish before dark hike planner

Moving time against a sunset you enter

A finish-before-dark planner puts a moving time on the clock. You enter the distance, the pace, the time you start walking, and the sunset time you looked up. The page adds distance times pace to the start time and subtracts that arrival from sunset. It does not compute sunrise or sunset from a latitude. Almanac times depend on date and place; type the time from a source you trust, then see whether the walk fits.

Inputs

Pace matches the distance unit. Breaks are not added. Sunset is the clock time you enter.

Result

Enter distance, pace, a start time, and sunset.

Disclaimer: Moving time only. Breaks, route-finding, and a wrong sunset time can erase the margin. This is not a promise you will finish in daylight.

Sunset is a clock time you bring. The drive to the trail is fuel math on the ClearQuip trip gas cost calculator.

How to use

  1. Enter the distance still ahead, not the distance you have already walked, unless you are checking the whole day from the start.
  2. Enter a pace you have actually walked, from the pace calculator or from a previous trip. The pace unit follows miles or kilometers.
  3. Set the start time and the sunset time. Change the sunset if the date or the valley is different from the forecast you read.
  4. Press Calculate. A negative margin means the moving time alone already passes sunset. Add breaks on top of that in your head; the form does not add them.

How it's calculated

Moving minutes = distance × pace
Arrival = start + moving minutes
Margin = sunset − arrival

Times are minutes from midnight on a 24-hour clock. A start of 2:00 p.m. is 14:00, which is 840 minutes. Six miles at 20 minutes per mile is 120 minutes, so arrival is 16:00. A sunset of 18:30 leaves a 150 minute margin before any break. If the margin is negative, the result shows how late the moving time is, and it does not wrap into the next morning as a success.

Climbing time that your flat pace ignores can be estimated with the Naismith calculator and then used as a longer effective pace. The drive to the trailhead is not in the margin; fuel for that drive is the ClearQuip trip gas cost calculator.

Worked example

Start at 2:00 p.m., 6 miles, 20 minutes per mile, sunset at 6:30 p.m. Moving time is 120 minutes, arrival is 4:00 p.m., and the margin is 2 hours 30 minutes. Start the same hike at 5:00 p.m. and the arrival is 7:00 p.m., which is 30 minutes after a 6:30 sunset. The hike did not get longer. The clock did.

Assumptions and sources

The planner uses the pace and the sunset you type. It does not call an almanac and does not apply civil twilight. The international mile, 1.609344 km, converts a kilometer pace into a per-mile pace before multiplying by miles. Breaks, photos, and time spent off the planned line are outside the product. If sunset is earlier than the start, the margin is negative even for a short walk.

FAQ

Does this look up sunset for my town?

No. Enter the sunset time yourself. A weather or almanac source for that date and place is the right input.

What about twilight?

The margin is against the sunset time you entered. If you want a buffer before sunset, enter an earlier time in the sunset field.

Why is my hilly hike optimistic?

A flat pace ignores climbs. Use Naismith’s rule for a time that includes ascent, then convert that time into a pace for this clock check.

Are breaks included?

No. Add them to the moving time yourself, or start earlier by that many minutes.

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