Guide
Unix time, calendar dates, VAT, and units: which calculator to open
Routes Unix-timestamp conversions, planning spans with working days, money-style VAT scenarios, and physical unit conversions to the matching pages.
Unix timestamps: instant math in UTC
Use the Unix timestamp converter when you are correlating logs, API fields, or database columns that store seconds or milliseconds since epoch.
Remember time zones: epoch values are absolute; human labels depend on the viewer’s offset.
Date difference and working days: calendars, not clocks only
Use the date difference tool when you care about spans between calendar dates, including working-day style counts for planning.
Working-day logic is domain-specific; verify holidays and locale rules for your jurisdiction.
VAT, discount, margin: money semantics
Use the VAT/discount/margin calculator when you are reasoning about tax-inclusive and tax-exclusive prices, simple discounts, or margin percentages.
This is a practical helper, not legal tax advice: rounding rules and rates vary by country and contract.
Unit converter: physical quantities
Use the unit converter when you need temperature or length conversions for engineering, travel, or classroom estimates.
Do not use currency tricks here: money workflows belong with explicit VAT/discount tools or finance systems.
Open calculators and converters
FAQ
Should I use Unix time for user birthdays?
Usually no. Birthdays are calendar dates; timestamps are great for exact instants, not recurring civil dates unless you model time zones carefully.
Does the VAT calculator know my country’s VAT rate?
You supply the rate. The tool helps arithmetic; compliance is your responsibility.
When do I pick working days versus calendar days?
Use working days when schedules exclude weekends or holidays by policy; use calendar days for elapsed time regardless of business closure.
Can I convert currencies in the unit converter?
No. Currency needs market rates and regulatory context; keep currency work in dedicated finance tooling.
Why are my logs one hour off after DST?
Daylight saving shifts wall-clock labels while epoch stays linear. Always log UTC epoch plus offset-aware rendering.