This chart is designed to compute the day session opening range high and low, of any duration (use the Button indicator to adjust the number of minutes of the opening range).

This works accurately on any session, any periodicity, and any symbol.  (as long as the day and full sessions are setup properly for the symbol).

Chart Definition: https://www.linnsoft.com/user/login?destination=node/8147

Chart uses MPD (with Session Statistics embedded) to get this variable duration, day session, opening range high (and low)...

And another version of this chart below draws bands between the ORH and ORL using the Bands Indicator.

Chart Definition: https://www.linnsoft.com/charts/cp-openrange-bands-vardur-es