In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.
study("Palladino/Booker Time Sessions", overlay=true) s = input(title="Session", type=session, defval="24x7") int = tostring(interval) timeinrange(res, sess) => time(res, sess) != 0 regular = blue notrading = na sessioncolor = timeinrange("1", s) ? regular : na bgcolor(sessioncolor, transp=75)