if you live in a cool dry area you can probably go 3+ weeks without problem - but then i dont want a dirty and stinky scalp to begin with

in a hot and humid area we can do probably 10-14 days at most... i have twice the thing fell off my head on day 16 -days 20 on my early days... lucky nobody was around otherwise it would have been disaster !!

since then i have been able to attach it much better and i still take it off every 14 days at most