Calculating and displaying event's duration with placeholder

Hi,

I have created a custom event template (and pasted it in the admin dashboard under the event format tab). It renders really well, but i was wondering if i could use placeholders to calculate the duration of the event (start time – end time). If not, can i use php inside that template ?

Many thanks,
Yvan

https://www.ads-software.com/plugins/events-manager/