Comment 6 for bug 2019026

FWIW I agree with Nick's preference (clean at boot && clean files older than 30d). Maybe we could make that 40d, as 30d is likely to be a time interval at which a lot of periodic things happen (e.g. an off-site backup). A retention period >30d is less likely be synchronized with it in an unlucky way.

Mounts with relatime (the default) update the atime unconditionally if the previous atime is >1day old, so no issues with that.