In case you missed the mailing lists announcement from the Operations Working Group, there will be a one hour period of downtime next Sunday (week today) :
We are planning to upgrade the software which runs the main OpenStreetMap database. Unfortunately, we cannot do this without a small amount of downtime. We would like to schedule this at a time which minimises the impact it will have, and plan to conduct the upgrade between 11:00 and 12:00 UTC on the morning of Sunday 12th March.
We expect that the database upgrade will not take the full hour, and we will endeavour to keep the site online for as much of that period as possible, and have it back to normal status as quickly as possible. However, there’s always the chance for things to go wrong, so please plan for the site to be down for the whole period.
The website and editing API will be affected, but other OSM services including the tile server, Nominatim, wiki, help and taginfo should continue to work as normal.
Apologies for any disruption this may cause and many thanks in advance for your patience,
Operations Working Group