The start date/time of an incident or alert might is not the exact one beacuse:

• Past data prior the installation of the Incidents UI is not loaded: alerts already firing at installation time, will have the installation time as start date, instead of the actual one
• Start date is affected by the time range dropdown: if an alert started 2 days ago, but you select "Last 1 day", the start date will start 24h ago. For performance reasons, only data in the time range is loaded
• Start and end dates are rounded to 5 minutes (already faced by https://issues.redhat.com/browse/OU-1039)

SHORT TERM SOLUTION

• Mitigate with UX: find alternative labels to "Start" and "end". For example, Detect at/until, or From/To

LONG TERM SOLUTION

• Load more data, 15 days? TO always display the rioght start date?