As a former 5th tier Raid Boss, Dialga's CP was 53,394. Its maximum capture CP in Bonus Challenge was 2,307 and 2,884 when encountered Pokémon was boosted by weather.
Dialga was available in Raid Battles from March 1st, 2019 until March 28th, 2019.[1][2]
Dialga's official release was delayed by three hours, although there were a handful of reports of it being available initially.[3]
The first reported Dialga raid had a timer that exceeded the standard 45 minutes[4], and an hour later world-wide sightings of Dialga were being reported with some having nearly a three-hour timer.[5]