Time-zone data and browser implementation
- Internet Assigned Numbers Authority (IANA): Time Zone Database — the canonical database of time-zone identifiers used by software systems.
- MDN Web Docs: Intl.DateTimeFormat — browser internationalisation API used to format a selected city’s current local time.
Tax and formal rules
Tax, VAT, sales-price, and education-grading rules are jurisdiction- and institution-specific. Apex Percent explains arithmetic only. For an actual obligation, use the relevant tax authority, school rubric, contract, or qualified professional rather than a generic online example.
How to use sources here
Source links support the stated methodology and help readers verify technical concepts. They do not turn a simple calculation into tailored professional advice. Use the contact form if a source is outdated or a link needs correction.