What is the allowable playtime on an LP album?
That's not an easy question to answer in a straightforward fashion. The most common play length is just under an hour; that's using standard formatting. Think 52 minutes if you want a specific. However, it is the technology that shapes it, and advances in vinyl technology may well allow more time on records. (If you mean any album, including CD, the common max goes up to 70+ minutes.)