For example, A Movie duration 1 hour and 25 minutes 15 seconds would be coded as ISO8601 format PT1H25M15S.
https://cinema.mrpuyal.com/movie/master-2021/
I create acf time filed and put the value in snip. but the schema output is not convert in iso8601 format. its display same custom filed value. please refer following link for acf.
https://support.advancedcustomfields.com/forums/topic/entering-and-displaying-time-duration/
Hey there,
and thanks for your message . I hope you’re doing well today.
SNIP does not convert any data loaded by ACF. Make sure that ACF returns the value the way you need it.
Greetings
Florian
how to convert and rich snippets schema fields
https://support.advancedcustomfields.com/forums/topic/entering-and-displaying-time-duration/