Dates are not timestamps.
Deadline, milestone and age tools use calendar dates in UTC-independent year/month/day form. The result states whether the start date is counted, whether the span is calendar or business days, and how month-end cases are handled.
Every tool carries its own trail.
Each calculator is generated from the registry and a versioned RulePack: inputs, assumptions, sources, retrieval date, review state, risk notes and boundary cases. L2/L3 outputs are intentionally phrased as references, ranges or prompts to verify.
Inputs stay in your browser.
There is no account, no input upload and no result database. Sensitive tools use neutral calendar titles and do not send health, substance, date or result values to analytics.
One build, three levels of trust.
General date math and low-risk planning.
Reference outputs with conditional context.
Legal, medical, safety, tax and sensitive contexts.
Start with the official page.
Tool pages expose their source IDs, organizations and retrieval dates. When a rule depends on a state, brand, product label or current policy, the page says so instead of pretending one default is universal.