Previously, fstrim was always called in a window of time shortly after midnight and with the requirement that the device is charging and idle, which was likely since most users would be asleep during these hours. However, this approach did not take into account the possibility that some people turn their devices completely off at night, which meant fstrim may never have an opportunity to run. To solve this, a more aggressive scheduling pattern has been created that ensures fstrim is run at boot-time after 3 days have passed without running it.