The window opens 20 May and closes 20 June—the summer solstice, the longest day of the year in the northern hemisphere. The endpoint is not arbitrary. The season has a turning point, and this virtual running challenge marks it.
Fifty kilometres on a Distance Lock across a month. Two formats in Season 262 carry the Ultra classification: .execution on the Pace Ladder and Solstice on the Distance Lock. Each demands a different kind of sustained discipline.
Distance Lock
The mechanic sets this online race apart from a standard multirun. Every session must land within a defined distance band—not just accumulate toward the total. A run that falls short of the lower boundary is rejected. A run that exceeds the upper boundary is also rejected. Neither counts toward the 50 km.
That constraint is not incidental. It is the central challenge of the format.
Planning an outing so that it lands inside the band requires more precision than planning a run of any convenient distance. Over a month, that calibration repeats with every session. There is no making up for a rejected run by running longer next time—each session still has to fit.
The month
The window is thirty-two days. That creates apparent room, but the surrounding calendar fills it unevenly.
Streets is still live when Solstice opens on 20 May; .execution is running; Goya closes on 22 May. Solstice’s second half—from early June onward—coincides with Thirteen, Rembrandt, and Mundial, plus the closing weeks of Nairobi. The back half of the window does not arrive quietly.
Carrying a significant portion of the 50 km into June means running inside a dense block with the Distance Lock discipline still active. Getting ahead of the distance in the first two weeks is worth something—not because June is impossible, but because it leaves more flexibility when the concurrent load is heavier.
Wasted attempts
In a standard multirun, an off day produces a shorter contribution that still counts. In this virtual running challenge, an off day that results in a run outside the band produces nothing.
That is a real cost across a month. A participant who misjudges the distance three or four times over the window has lost those sessions entirely—not just logged a suboptimal split. The total has to reach 50 km from valid sessions only; there is no backdating, no adjustment, no resubmission.
Session design as a repeating decision
The distance band is fixed; the session plan is not. Factors that affect how far a run actually lands—conditions, fatigue, terrain, pacing judgment—vary every day. Some sessions will push close to a boundary. Some will miss.
Managing that uncertainty across multiple weeks, while other virtual running competitions are also active, is the operational challenge that Solstice imposes above and beyond the physical distance.
Frequency trade-offs
More sessions bring the band discipline into sharper relief more often but allow for smaller individual calibration errors. Fewer sessions require larger individual band targets, which may be harder to hit precisely but reduce the total number of times the constraint must be negotiated.
Neither frequency structure removes the discipline. It redistributes where the risk concentrates.
After 20 June
23:59 UTC on 20 June closes both the virtual race and the window. Results pass through verification; provisional standings can shift until the race reaches Results out.
20 June is the solstice—the day the season turns. Whatever the distance record shows at that point is what the race carries forward.
What Solstice requires
A complete result here asks for two things that a standard multirun does not stack together: the volume (50 km) and the precision (each session inside the band). Either element missing produces an incomplete entry.
That combination, sustained across a month at the far end of a long season, is what the Ultra classification reflects.
