According to
https://www.theregister.co.uk/2020/0...ys_stale_data/ "The US Federal Aviation Administration has ordered Boeing 787 operators to switch their aircraft off and on every 51 days to prevent what it called 'several potentially catastrophic failure scenarios' – including the crashing of onboard network switches."
The FAA directive is here
https://ad.easa.europa.eu/ad/US-2020-06-14, and comes into effect on Tuesday 7th April 2020