GMT windows and renewal markers
Subscription KPIs and cash reports can move when clocks and renewal tags move—not when revenue does.
Teams serving subscribers in the United Kingdom often mix UTC warehouse timestamps with GMT finance calendars. A cohort day that spans the wrong midnight shifts every MRR and churn cell without anyone shipping a pricing change.
Missing or duplicated renewal markers create similar ghosts: returning subscribers appear as new cohorts, and month-one rates look healthier or worse depending on merge rules.
Before celebrating a revenue lift after a platform migration, list SDK versions, identity rules, timezone settings, and renewal tags beside the chart. If those moved, treat the chart as suspect until you rebuild from raw events.