Hi @itsmelmon ,
I believe this would be possible by using the start end end date an comparing it to the current date time with the utcnow(). However, in order to make this to work I am converting the times from Shifts and the current time to ticks per minute.
In my example I am using the List Shifts action btw.
1. Add a List All Shifts action
2. Add a condition action and add the following two expressions to it. The first one is looking at the start time and the second one at the end time of the shift. In both cases I am converting it to ticks per minute (that's why I am dividing it by 600000000). And I am using an empty to check to ignore the field value if it's empty. I noticed that some shifts where listed without start times.
Update expression below. Had a small typo.
if(empty(items('Apply_to_each')?['sharedShift/startDateTime']), 0, div(ticks(items('Apply_to_each')?['sharedShift/startDateTime']),600000000))
is less than or equal to
div(ticks(formatdatetime(utcnow(), 'yyyy-MM-ddTHH:mm:ssZ')), 600000000)
And I am also using
if(empty(items('Apply_to_each')?['sharedShift/endDateTime']), 0, div(ticks(items('Apply_to_each')?['sharedShift/endDateTime']),600000000))
is greater than or equal to
div(ticks(formatdatetime(utcnow(), 'yyyy-MM-ddTHH:mm:ssZ')), 600000000)

3. Collected the assigned to user id and post your message to teams 🙂
Hope this helps a bit?