FOCUS column
BillingPeriodStart
The inclusive start of the billing period the row belongs to: the interval, normally a calendar month, that a single invoice covers. It is the anchor for month-end reporting, because every row in a period sums to that period’s invoice regardless of when the usage itself happened within it.
Example
Every row on the September invoice carries 2026-09-01T00:00:00Z here, even a charge for usage on the last day of the month.
Where it comes from, per export
The export column that feeds BillingPeriodStart in each format the platform ingests, and the transform applied. A format with no row does not carry the column; the value is then absent rather than guessed.
| Export | Source column | Transform |
|---|---|---|
| AWS Data Exports, FOCUS | BillingPeriodStart | as is |
| Azure Cost Management, FOCUS export | BillingPeriodStart | as is |
| Azure Cost Details (actual cost) | BillingPeriodStartDate | parsed as a date (MM/dd/yyyy) |
| Azure Cost Details (amortized cost) | BillingPeriodStartDate | parsed as a date (MM/dd/yyyy) |
| Google Cloud detailed billing export | invoice.month | parsed as a date (yyyyMM) |
How Runcost uses it
Runcost groups statements, forecasts and reconciliation by billing period, so a statement is one invoice’s worth of allocated cost.
Related columns
About this reference
Generated from the column contract and provider rules that Runcost runs, and written by Faisal Saleem, Founder. The normative definitions are in the FinOps Foundation’s FOCUS specification at focus.finops.org.