Could you find downtime by looking for a store where COUNT(*) or heartbeats is < 48 in a 24 hour period? or something like that

so like (pseudo code):

SELECT storeNumber, TIME_FLOOR(__time, 'P1D') as "t", count(*) AS "heartbeats" FROM XXX WHERE eventName = 'HEARTBEAT' GROUP BT 1, 2 HAVING "heartbeats" < 48