BO_EXPIRY_VDUB_v2 - Projection

//@version=2
study(shorttitle="BO_EXPIRY_VDUB_v2", title="BO_EXPIRY_VDUB_v2", overlay=true)
trade_session = input(title='Trade Session:', type=string, defval='0400-1500', confirm=false)
istradingsession2 = not na(time('1', trade_session))
bgcolor(istradingsession2?black:na, transp=60, offset=100, title="Trading session")
//
tf = input('240' )
tf_bool = na(tf_bool[1]) ? 0 : change(time(tf)) and tf_bool[1] == 0 ? 1 : change(time(tf)) and tf_bool[1] == 1 ? 0 : tf_bool[1]
bgcolor(tf_bool == 1 ? gray : silver, transp=70, offset=100, title="BO Expiry")