Calculator requirements
- A clearly stated purpose and audience.
- Validated inputs and understandable results.
- The formula or method used.
- A worked example with reproducible numbers.
- Rounding rules, assumptions and known limitations.
- Frequently asked questions that add genuine context.
Testing
Calculator logic should include deterministic test cases covering ordinary values, zero values, boundary values and overnight time handling where applicable.
Current-data policy
Tools depending on taxes, statutory rates or jurisdiction rules must display their effective date, identify primary sources and be reviewed when rules change. A calculator must be withdrawn or clearly marked when its data cannot be verified.
Source hierarchy
- Primary government, statutory or official technical sources.
- Employer plan documents for policy-dependent calculations.
- Documented MyClockLedger methodology for general arithmetic.
Review status and versions
Sensitive calculations display a formula version, review date, effective date, reviewer, scope and source basis. Material formula changes are recorded in the public formula change log.
Corrections
Material formula or data corrections should be documented in the project release notes and deployed promptly.