Google calendar on phone not syncing with shared c...

[abbi]

In airtable, I've programmed a calendar with dates and times for specific events.
The formula is as follows: 

IF({Override horaire cour 1}=0,IF(Ordre="1", DATETIME_PARSE(DATETIME_FORMAT({début},'MM/DD/YYYY')&' '&{Horaire c1h1}), DATETIME_PARSE(DATETIME_FORMAT({début},'MM/DD/YYYY')&' '&{Horaire c1h2})),DATETIME_PARSE(DATETIME_FORMAT({début},'MM/DD/YYYY')&' '&{Override horaire cour 1}))

When I install the calendar in my application, all the appointments are 1 hour later.
How can I fix this?