You close the lid on a healthy battery, and in the morning the Mac is warm to the touch, the fans have clearly been working all night, and 20–30% of your charge has vanished. If that started right after you installed macOS 27 Golden Gate, there is a specific, well-documented suspect behind it — two background processes called dasd and appstoreagent stuck in a tight loop that reportedly kicks in at midnight and runs until morning.
Some users report this is not the generic "my Mac runs hot" problem, but a distinct pattern and, crucially, a documented fix. Below: how to prove in two minutes that this is what is happening on your Mac, the exact Terminal workaround that stops it, how to undo it, and which other overnight-heat causes to rule out first.
What the Symptom Looks Like
The clearest description comes from a MacRumors thread started on 27 September 2026. The original poster saw CPU usage spike "exactly at midnight" with appstoreagent and dasd as the culprits — on both a MacBook Pro and a MacBook Air. Leaving both machines running overnight with a system monitor open, they watched the load drop again at 9 AM. Other members confirmed the same pattern on a Mac Studio and another MacBook Pro.
The tell-tale pattern:
- Mac is warm or the fans are audible in the morning despite the lid being closed all night.
- Battery has drained far more than a normal night of sleep should cost.
- It began after upgrading to macOS 27 — and the timing repeats nightly, reportedly starting around midnight local time.
- You may never see the CPU spike itself unless a monitor is running, but as one forum member put it, "you will definitely notice your battery running down faster."
If your Mac runs hot during the day, or the heat started days after the upgrade and never stops, this particular bug is probably not your problem — skip to the "other causes" section below.
What dasd and appstoreagent Actually Do
Before running anyone's Terminal commands, it helps to know what you are poking.
dasd is the Duet Activity Scheduler daemon — the switchboard for macOS background work. Time Machine backups, software-update clean-up, security scans and dozens of routine maintenance jobs all flow through it. When dasd burns CPU, it almost always means something is feeding it work over and over.
appstoreagent is the App Store's background helper. It checks for app updates, handles automatic downloads and verifies licences, and it is normally invisible at close to 0% CPU. One of its jobs is bookkeeping for Apple Arcade — and that is where this bug lives.
Unverified User Theories About the Cause
Note: The following technical details are unconfirmed user speculation from forums, not verified by Apple or reputable sources. The exact cause of the reported overheating has not been established.
Sources
Several people have independently traced the loop to the same place. The task involved is com.apple.appstored.ArcadeResetPO, an Apple Arcade bookkeeping task. After it runs, a preference in the com.apple.appstored domain called ArcadePayoutResetDate is supposed to advance to the next cycle. Instead, it stays locked to a past timestamp.
Because the date is in the past, dasd treats the task as permanently overdue and runs it immediately. appstoreagent then re-registers the same expired deadline. The cycle repeats — reportedly 70 to 100 times per second — pinning a full core, flooding the system log, generating heat and draining the battery. Two independent investigators reached the same conclusion, and the bug was already visible in macOS 27 developer betas back in June 2026, which means it shipped in the release rather than arriving with a later update. As of writing, Apple has not published a known-issue note for it.
How to Confirm This Is Your Problem (Nothing Changes Yet)
Do these in order. Nothing in this section changes any setting. Ideally run the first two while the Mac is misbehaving — shortly after midnight, or first thing in the morning before you open anything.
1. Check Activity Monitor
Open Activity Monitor from Applications > Utilities, click the CPU tab and sort by % CPU. Look for dasd and appstoreagent both near the top with sustained usage — reports describe a full core, so near 100% on a multi-core machine is the pattern. Note that dasd runs as root: if you only see your own processes, set View > All Processes. A huge accumulated CPU Time next to appstoreagent is a strong clue even after the spike has passed, because that column keeps counting.
2. Confirm from Terminal
Terminal gives you text you can paste into a forum thread. Ask for two samples of top and read the second (the first is an average since boot):
top -l 2 -n 10 -o cpu -stats pid,command,cpu,timeIf dasd and appstoreagent sit in the top few while the Mac is otherwise idle, that matches the bug. A shorter alternative:
ps -axo pid,pcpu,time,comm -r | head3. Read the Arcade date — the decisive test
This checks the reported cause instead of the symptom:
defaults read com.apple.appstored ArcadePayoutResetDate
date -u +"%Y-%m-%dT%H:%M:%SZ"The first line prints the stored date (e.g. 2026-09-26T22:00:00Z); the second prints the current time in the same format so you can compare by eye. How to read the result:
- Stored date is in the past while dasd and appstoreagent are busy: that matches the reported bug.
- Stored date is in the future and the processes are quiet: this bug is not what is happening.
- Stored date is in the future and the processes are still busy: something else is going on — use the "other causes" table below.
- The key does not exist: the App Store machinery has not created it yet (common if you never use the App Store or Apple Arcade). Not evidence either way.
Save this output before changing anything — it is your record of the original value.
4. Peek at the unified log
To see how often dasd is firing, count its log lines in a single minute:
log show --predicate 'process == "dasd"' --last 1m --style compact | wc -lOn a healthy Mac that number is modest. If this bug is active, expect a flood. For the most specific filter, search for the task name directly:
log show --predicate 'eventMessage CONTAINS "ArcadeResetPO"' --last 2m --style compact | head -50If ArcadeResetPO appears dozens of times in a minute, you have confirmed the reported bug.
The Fix: Push the Date Forward and Restart the Agent
The community workaround is one defaults write plus restarting appstoreagent. It moves the stuck deadline into the future, so dasd stops seeing the task as overdue. It is reported to hold for as long as the date you choose — seven days is the common pick, after which you repeat it if needed.
- Write a future date into the preference (seven days from today is 21 October 2026):
defaults write com.apple.appstored ArcadePayoutResetDate -date "2026-10-21T00:00:00Z" - Restart the agent so it picks up the new value:
The process relaunches on its own — that is normal. Killing it alone, without the date change, only buys minutes: launchd restarts it and the loop resumes.killall appstoreagent - Re-run step 3 from the diagnosis section and confirm the stored date is now in the future, then watch Activity Monitor for a few minutes. The dasd/appstoreagent load should settle.
To undo it: delete the key and restart the agent again:
defaults delete com.apple.appstored ArcadePayoutResetDate
killall appstoreagentThis is a workaround, not a permanent repair. The real fix has to come from Apple.
Does macOS 27.0.1 Fix It?
Apple's macOS 27.0.1 update (build 26A434) is described as fixing unspecified bugs, but nobody has yet posted a confirmed result for this specific issue. Do not assume the update resolves it — test on your own Mac using the diagnosis steps above. Either way, keep Software Update switched on: official patches are still the only durable fix, just as upgrading from Windows 11 24H2 before support ends is the safe move on the Windows side. Update bugs that ship in release builds are a cross-platform headache — this month's Windows 11 update crashing games is another reminder.
If It Is Not This Bug: Other Overnight-Heat Causes
Several ordinary things heat a Mac overnight. Match your symptom to the process name in Activity Monitor:
- mds / mds_stores / photoanalysisd near the top: Spotlight re-indexing or Photos analysis after the upgrade. This settles on its own within a day or two — let it finish.
- backupd busy: a Time Machine backup running overnight. Normal; check that backups complete.
- bird / cloudd busy: iCloud sync catching up. Also temporary.
- Heat only when plugged in, or the Mac wakes by itself: check System Settings > Battery > Options for "wake for network access" and scheduled wake events. A third-party menu-bar helper or an external display can also keep the Mac from sleeping properly.
- Heat that never stops, day and night: that points at something else entirely — a runaway app, dust-clogged cooling, or failing hardware. Run Apple Diagnostics (hold D at startup on Intel, or hold the power button on Apple silicon and choose Options > Apple Diagnostics).
Frequently Asked Questions
Why is my MacBook hot when I wake up in the morning?
If it started after the macOS 27 update and repeats nightly, the most likely cause is the reported dasd/appstoreagent loop: a stuck Apple Arcade deadline makes the scheduler re-run a background task 70–100 times per second all night, pinning a CPU core. Confirm it with the defaults read com.apple.appstored ArcadePayoutResetDate check above.
What is dasd on Mac and why is it using so much CPU?
dasd is the Duet Activity Scheduler daemon — macOS's switchboard for background jobs like Time Machine, update clean-up and sync passes. High dasd CPU almost always means some other task is feeding it work repeatedly. In the macOS 27 overnight-heat reports, the feeder is the stuck ArcadeResetPO task owned by appstoreagent.
What is appstoreagent on Mac?
appstoreagent is the App Store's background helper: it checks for app updates, handles automatic downloads and verifies licences, including Apple Arcade bookkeeping. It normally sits near 0% CPU. Sustained high CPU from appstoreagent on macOS 27 — especially paired with dasd — is the signature of the overnight loop described in this guide.
Is it safe to run defaults write on my Mac?
The command in this guide only changes one preference value in the App Store's own settings domain (com.apple.appstored), moving a date forward. It does not touch system files, and it is fully reversible with defaults delete. Save the original value first so you can restore it exactly.
Will the dasd bug come back after I fix it?
Possibly. The workaround holds for as long as the date you set — reports suggest around seven days — because nothing stops the date from getting stuck again. Repeat the fix if the symptoms return, and file the bug with Apple via Feedback Assistant so an official fix ships.
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