Generate a deferred revenue waterfall from billing-system data

Steps

1. Extract all invoiced or charged amounts with billing_date, service_start_date, service_end_date, and amount from your billing system via API or data export.
2. For each charge, compute the daily or monthly recognition rate: recognition_rate = amount / number_of_service_days (or months); store the rate alongside the charge record.
3. Build a period matrix: for each fiscal period from the earliest service_start_date to the latest service_end_date, calculate the portion of each charge that falls within the period using date overlap logic (min(service_end, period_end) - max(service_start, period_start)).
4. Aggregate by period to produce the waterfall: deferred_revenue_opening = sum of unrecognized amounts at period start, recognized_in_period = sum of period allocations, deferred_revenue_closing = opening + new_billings - recognized.
5. Reconcile the closing deferred revenue balance against the GL deferred revenue account for each period and flag variances exceeding a configurable materiality threshold for investigation.
6. Output the waterfall as a structured report (JSON, CSV, or directly as GL journal entries) organized by product line or customer segment for management and auditor review.