Dear Paweł Walkowiak, thank you for your contributions to OSM. This is the fifth time you have changed this one node: https://www.openstreetmap.org/node/12250472179/history - don't over-do it, we're not looking for millimeter precision ;)

Also, you don't have to save every single change you make. Just edit a few buildings and then upload all in one go.

For the "changeset comment" field, don't put tomorrow's date - instead, put an explanation of your edit (e.g. "corrected building locations in CITYNAME" or so).