Events are only retained for 24 hours, after which they are deleted.
It was estimated that this would satisfy most use cases and keeps resources as
available as possible. If you would like to have a longer record of events, setup
your account to post to Google Analytics.
Why are there event limits?
These are in place to protect the availability of the service.
Since alarms have to query through events to determine if one should be triggered
at each run, the number of events to query through has a direct impact on the
system performance. If an excessive number of events were allowed, the system may crash.
Why are there limits on how often alarms run?
The number of times alarms run is limited to prevent our servers from
getting overloaded and to enable HitHub the ability
to serve many people. The more often an alarm runs, the more server resources it
demands, which is why those higher alarm run frequency accounts cost more.