Date, time & color
Find the right time. Pick the right shade. Choose a section to find the right tool quickly.
Date difference calculator
Find the whole-day difference between two calendar dates.
Add days to date
Add or subtract a whole number of calendar days.
Age calculator
Calculate calendar age on a date you choose.
ISO week number
Find the ISO week and ISO week-numbering year.
Leap year checker
Check Gregorian leap-year rules.
Time zone converter
Display a specified UTC instant in an IANA time zone.
Duration converter
Convert a duration in seconds into days, hours and minutes.
Countdown calculator
Calculate remaining time between two explicit instants.
Color HEX to RGB
Convert a six-digit hexadecimal color to RGB channels.
Color RGB to HEX
Convert integer red, green and blue values to hexadecimal.
Color HEX to HSL
Inspect the hue, saturation and lightness of a color.
Color HSL to HEX
Convert hue, saturation and lightness to hexadecimal.
WCAG contrast checker
Check text/background contrast using WCAG relative luminance.
Complementary color
Find a hue-opposite color in HSL.
Analogous color palette
Generate nearby hues at −30°, 0° and +30°.
Triadic color palette
Generate three hues spaced 120° apart.
Color tint generator
Blend a base color toward white in five steps.
Color shade generator
Blend a base color toward black in five steps.
CSS gradient generator
Generate a two-color linear-gradient declaration.
Color mix calculator
Interpolate two colors in sRGB channel space.