UA Ledger · Measurement Lab · draft for review

Show how a UTC event crosses a reporting-day boundary

Synthetic teaching inputs. No real campaign results or industry defaults. Change the values to inspect the model. Calculations run locally; this page sends no data and does not retain inputs after closing.

Enter the UTC hour and the reporting offset in hours. Add them, wrap the result into a 24-hour clock and separately count the day offset. Keep those outputs together: a local hour of one without its next-day marker loses the very information the exercise is intended to reveal. Use a real timezone library for production timestamps and daylight-saving transitions.

Calculated outputs

Assumption sensitivity

Only offset varies; all other inputs are held constant. This is not a probability range.

Equations

• Local hour: ((hour+offset)%24+24)%24
• Day offset: Math.floor((hour+offset)/24)

Additional constraints: (hour<24) && (offset<=14). The field minimums also apply.

Limits

Fixed offsets do not capture daylight-saving changes or historical timezone rules. This exercise does not transform real event timestamps and cannot certify a platform’s date-grouping configuration.

Google Analytics BigQuery Export schema · primary documentation checked 19 September 2026.