6.0 release Dec-3-2021
6.1 release Apr-12-2022 (131 days)
6.2 release Aug-23-2022 (133 days)
6.3 release Jan-10-2023 (140 days)
6.4 release May-23-2023 (133 days)

As Koros said, that's 4.4 months between patches.

If they release patch 6.5 in early October as announced in the Live Letter, it would be on track for the 133-140 day cycle depending on the exact date.