Hi @GregLmt ,
I have tried to come up with a formula for the following sample.
10am-12am// 2pm-5pm
9am-12am//1pm-4pm
9am-11am//12am-3pm
9am-1pm
REGEX_EXTRACT({durationText},"^\\d{1,2}\\w{2}-(\\d{1,2})")-
REGEX_EXTRACT({durationText},"^(\\d{1,2})\\w{2}-")+
IF(REGEX_MATCH({durationText},"^\\d{1,2}am-\\d{1,2}pm.*"),12)+
IF(FIND("//",{durationText}),
REGEX_EXTRACT({durationText},"//\\s?\\d{1,2}\\w{2}-(\\d{1,2})\\w{2}")-
REGEX_EXTRACT({durationText},"//\\s?(\\d{1,2})\\w{2}-")+
IF(REGEX_MATCH({durationText},"^.*//\\s?\\d{1,2}am-\\d{1,2}pm"),12)
)