Who wakes your Mac at night?

Measured 14 August 2026 · six consecutive nights of one MacBook Pro's own power log, then seven nights of a second Apple silicon Mac for comparison · every number below is from those logs, and the command to reproduce it on your own Mac is at the bottom

Your Mac does not sleep through the night. It wakes, does something for half a minute, and goes back to sleep — dozens of times, without lighting the screen or making a sound. macOS records every one of these wake-ups and the service that asked for it, in a log almost nobody reads.

Here is what six nights of that log looked like on the machine this page was written on.

The numbers

Who asked

At the surface, three system daemons place nearly all the requests: powerd (54%), dasd, the task scheduler (23%), and mDNSResponder, the network discovery service (20%).

But those are messengers. The interesting part is the info= field, where the scheduler records whose task it is actually running. Across the week, the most frequent real requesters were:

Not one of these is a bug, and not one of them is an app you installed. This is the machine keeping calendars, search, network address and diagnostics current while you sleep — the everyday cost of a computer that's ready when you open it.

The detail worth pausing on: on this machine the top requester isn't the search indexer everyone blames, it's the Calendar's travel engine, refreshing on a timer 236 times in a week. Nothing in any settings pane mentions it. That's the value of the log — it replaces folklore about where the charge goes overnight with names.

Then we ran it on a second Mac, and almost nothing matched

Before publishing we repeated the whole analysis on a different Apple silicon Mac, seven nights, same filters. We expected the numbers to move a little. They moved a lot:

Three times the wake-ups, a sixth of the duration each, a different culprit — and the search indexer didn't even make Mac 2's top six. So the honest headline isn't "Calendar wakes your Mac". It's this: the answer is specific to your machine, and it is written down on your machine. Which is exactly why a page like this is worth less than five minutes with your own log.

What this does and doesn't prove

These are two Macs, not a population. Yours will differ again — more calendars, more mail accounts or a busier network mean more wake-ups; Power Nap off and Wi-Fi disconnected mean fewer. Treat the numbers as a demonstration of what the log contains, not as an average of all Macs. We're not going to dress up n=2 as a study.

Even the method has a tolerance. Recounting Mac 1 with slightly different episode filters moved the totals a few per cent (132 wake-ups instead of 124, 36 seconds instead of 30). Same log, same machine, defensible choices about what counts as one wake-up — and the third digit moves. We publish the filters (in the script below) precisely so that you can disagree with them.

We deliberately do not price a single wake-up. It's the number everyone wants — "so how much battery did those 124 wakes cost?" — and it can't be measured honestly: macOS reports charge in whole percent, and a 30-second wake doesn't move a whole percent. Anyone who gives you milliwatt-hours per wake is modelling, not measuring. What can be measured honestly is the count, the duration and the requester's name — so that's what we report.

Silent doesn't mean harmless, and it doesn't mean harmful either. Dark wakes are the design working as intended. The reason to know about them is the outlier case: when one service starts waking the machine hundreds of times or holding it awake for minutes at a stretch, that shows up in exactly this log — and nowhere else in the interface.

Reproduce it on your own Mac

No app needed for the raw material — macOS keeps the log itself. In Terminal:

pmset -g log > ~/Desktop/power.txt

Then look for the lines labelled Wake Requests — each one carries process= (which daemon asked), wakeAt= (when) and often info= (whose task it really is). Lines containing DarkWake are the silent wake-ups. That's the whole trick, and it's been sitting in every Mac for years.

What WattMate adds is that you don't have to do this: it reads the same log and turns a night into plain language — how long the Mac slept, how often it woke, who asked, and how much of that time carries a name. Alongside the part of the product that measures the waking day: which app is using the battery in watts, and what quitting it is worth in minutes, verified afterwards.

Methodology and limits for everything we measure: how we count. Related: what to expect after the macOS 27 update · does quitting apps actually help?

Journalists and researchers: the raw log analysis behind this page is available on request — [email protected]. We'd rather you check it than trust it.