calculated 20 days but it depends on luck heavily - could be 10 days or 35 days

but as the new wallet seems to work fine and everybody should had enough time to update the dev's might change the block again to an earlier one if possible - they were already listening to community when there initial goal for the targeted block was by far to late in the future but i understand the dev's too that they want to ensure that people / pools / ... have enough time to update first and to see if the updates run fine (work on my own in IT business).