What does sleeping cost your builders?

What I ran

I built two villages that have just reached their Town Hall, one at 12 and one at 15, with everything of the hall before it maxed and five builders: 157 and 196 buildings, traps, heroes, troops, spells and pets. Then I let the planner schedule them with the Max strategy for 60 days under seven sets of offline hours and counted every builder-hour a builder stood free because I was away. Five builders over 60 days is 7,200 builder-hours.

Each profile ran two ways. Planner is ClashClock as it ships: it looks at your offline hours when it picks the next upgrade. Blind is the same planner told to ignore them when it picks. It still cannot start anything while you are away, so a builder that finishes at 03:00 waits for you. That is the queue of someone who chooses upgrades by worth and nothing else.

Every number is the mean of 12 runs that begin at different moments of the week, with five upgrades already running at random progress. The exception is the Max Town Hall day near the end, a mean of 6 runs.

The answer: a few builder-hours in two months

Always awake, five builders work 300 builder-days in 60 days. With 8 hours of sleep and the planner at Town Hall 12 they work 299.7 of them. Spread over the hours you sleep, that is the figure to remember:

So an hour of sleep costs a builder about 10 seconds when the order is right (0.16 and 0.18 minutes). Without it, a Town Hall 12 builder loses almost 3 minutes of every hour you sleep and a Town Hall 15 builder about half a minute. Across the 12 runs, the planner's idle time for 8 hours of sleep at Town Hall 12 ran from 2 to 14 hours and the blind queue's from 82 to 147. The ranges do not touch.

To check the blind number without trusting my own switch, I made no schedule at all. I took the plan made for an always-awake player and walked each builder through the same steps in the same order, starting a step only when its builder was free and I was online. That gave 124 idle hours at Town Hall 12 for 8 hours of sleep, against 114 for the blind planner, and 19 at Town Hall 15, against 19.

Why the night is cheap, and why Town Hall 12 pays more

A builder only loses time when an upgrade ends while you are away. Most upgrades are long. In the Town Hall 12 schedule, 64% of the steps take a day or more and carry 89% of the builder time. At Town Hall 15 it is 96.5% of the steps and 99.7% of the time. Most of them last a whole number of half-days: 66% of the steps (88% of the builder time) at Town Hall 12 and 98% (99.9%) at Town Hall 15.

That has a side effect. A builder who starts a 96-hour upgrade when you wake up is free again when you wake up four days later. One who starts an 84-hour upgrade at 19:00 is free at 07:00. Once a builder is in step with your day, long upgrades keep it there. The builders that wait are the ones that start an odd length before bed, like a 3-hour level, or whose long upgrade lands on the wrong side of midnight.

blind
  Inferno Tower 5->6
    Sun 12:29 + 96 h -> Thu 12:29
  X-Bow 5->6
    Thu 12:29 + 84 h -> Mon 00:29
  Hidden Tesla 9->10
    Mon 07:00 + 48 h -> Wed 07:00
    (waited 6.5 h for you)

planner
  Inferno Tower 2->3
    Sat 12:29 + 48 h -> Mon 12:29
  Eagle Artillery 2->3
    Mon 12:29 + 168 h -> Mon 12:29
  Hidden Tesla 9->10
    Mon 12:29 + 48 h -> Wed 12:29

Town Hall 12 has more hours-long levels left, so more chances to end in the night. The higher the hall, the fewer:

The planner stays between 0.1% and 0.3% in every hall I tried. I left Town Hall 11 out of the chart: its builders run out of work inside the 60 days because the Laboratory sets the pace, so its idle share is not comparable.

A rushed village behaves the same way. A Town Hall 13 with Town Hall 10 buildings lost 0.3% with the planner and 0.7% blind. A Town Hall 15 with Town Hall 12 buildings lost 0.1% and 0.2%, and a Town Hall 15 with a sixth builder 0.1% and 0.3%.

The next Town Hall: Rush barely moves, Max follows the laboratory

I also asked the Rush strategy, which sends the Town Hall up as soon as the game allows it, how many days it takes to stand on the next hall, counted from the start of the plan. The shift is against the always-awake run of the same village.

The Town Hall is one long upgrade that starts as soon as its requirements stand, so there is nothing to bridge. Across the 12 runs the largest delay was 9 hours. Sleep sometimes even brings the day a little earlier: at Town Hall 12 the mean shift is below zero for 6, 8 and 10 hours of sleep. I did not trace why, and I would not read anything into an hour either way.

Under Max the Town Hall goes last and waits for the worker whose last step ends the hall. The laboratory ended the hall last in all 6 runs I checked, in both villages, always awake and with 8 hours of sleep. So the day the Town Hall can start follows the laboratory's idle hours, not the builders'.

At Town Hall 12 the laboratory accounts for about those days. With 8 hours of sleep it stood still for 10 hours in each 60 days, which over 138 days comes to roughly 24 hours, a day. With four check-ins it stood still for 19 hours in 60 days, roughly 44 hours over 138 days, or 1.8 days. Run by run, four check-ins delayed the Town Hall by 1.4 to 2.2 days at Town Hall 12 and by 2.2 to 2.5 days at Town Hall 15.

Four check-ins a day cost more than sleep

The profile that hurt most is not the one with the most sleep. Opening the app four times a day for half an hour is offline for 22 hours a day. At Town Hall 12 it cost the planner 70.8 builder-hours (1.0%), 7.5 times the 9.4 that 10 hours of sleep did, and the blind queue 205 (2.8%). At Town Hall 15 it cost 0.2% and 0.6%.

Two planner limits show up here. The Laboratory is not shielded: the planner picks research without looking at your hours, and with 8 hours of sleep at Town Hall 12 the lab stood still for 10 hours in 60 days (0.7%), against 6 hours for all five builders together. And with online windows this small the look-ahead stops helping: at Town Hall 14 with four check-ins the planner lost 0.9% and the blind queue 0.7%.

What this means for your village

• From Town Hall 13 up, the night is not where your builders lose time. Do not save an upgrade for bedtime or set an alarm for one that ends at 03:00.
• At Town Hall 12, hours-long levels are common. Before bed, give a builder a day-long upgrade rather than a 3-hour one. That is the 1.5 percentage points the planner saves.
• Opening the app a few times a day costs more than sleeping, even with the planner choosing the order: 1.0% against 0.1% at Town Hall 12.
• Under a rush, sleep moves the day your next Town Hall stands by hours, not days: 2.4 hours at most on average and 9 in the worst run, so a rush needs little adjusting for sleep. Under Max the Town Hall waits for the laboratory, which stands still while you are away: about a day for sleep at Town Hall 12, up to 2.4 days for four check-ins a day.

Method and limits

These are two simulated villages, not yours. They show how the planner treats a night.

• Villages: a Town Hall just reached, everything of the hall before it at its top level (from Town Hall 17, as the game files and the app's data have it, the merged defences stand merged and the Eagle Artillery is part of the hall), five builders, no helpers, Gold Pass, potions or events. Walls take no time. Max gives the builder time, Rush the Town Hall date.
• Always awake is an upper bound. A builder is never idle there, as if you opened the app the second an upgrade ended.
• Resources never stop a start. In the game a builder also waits for gold or elixir, and the planner's night-bridging pick may then be one you cannot afford. With resource limits the real figure could be higher or lower; this run does not measure it.
• Blind switches off two lines of the scheduler for the run: the waiting time an upgrade would cause when it ends, and the look-ahead to the next offline stretch. A builder still cannot start while you are away. Nothing in the app changes.
• I count builder time, not what the builder works on. By the planner's own importance score, the work done in 60 days is within 1% of always awake for 8 hours of sleep (99.6% at Town Hall 12, 100.2% at Town Hall 15). That is the planner grading itself.
• I count builder-hours, not the day a hall is maxed. In these villages the laboratory ends the hall last, so that day follows the laboratory's idle hours, not the builders'.
• The planner is greedy: each time a builder frees up it picks the best-looking step and never goes back (see How ClashClock works). These are results for this planner, not for the best possible order, and a better one may exist.