Add or subtract days from any date. Get the resulting date instantly — useful for deadlines, scheduling, and planning.
Add or subtract hours and minutes from a starting time. Perfect for scheduling, project planning, and time tracking.
Find the ISO week number for any date. Also shows the day of the week and the current week of the year.
Timers (countdown, event countdown, stopwatch with laps), date math (add/subtract days, difference calculator, week number), converters (date↔timestamp), and time math (add/subtract hours/minutes, duration between times). (Time converter has its own dedicated page.)
Calculate the area and perimeter of a rectangle from length and width. Simple geometry for construction, design, and planning.
Computes exact age in years, months, days, hours, minutes, and seconds from a given birth date relative to any target date.
Date Addition Calculator lets you add or subtract days from any date. Get the resulting date instantly — useful for deadlines, scheduling, and planning.. Everything runs inside your browser — nothing is uploaded to a server. It works on any device with a modern web browser.
Add or subtract days from any date. Get the resulting date instantly — useful for deadlines, scheduling, and planning. It's ideal for developers, designers, and anyone who needs to add or subtract days from any date without installing software or sending data to external servers.
Direct text entry, file upload, or URL-based input — depending on the tool. All numeric values are entered through input fields with real-time updates.
Yes. After the initial page load, Date Addition Calculator runs entirely on your device with no internet connection needed. All processing is done locally.
Tools cover JavaScript, CSS, HTML, SQL, Python, JSON, XML, CSV, and more. Check individual tool descriptions for specifics.
No. All code processing — formatting, minification, conversion, hashing — runs locally in your browser.
Yes. Since processing is local, performance depends on your device. Most operations handle large files without issue.
Yes. SQL uses sql-formatter, JSON uses native JSON.parse, and other formatters follow widely adopted formatting rules.
Yes. All developer tools work fully offline after the initial page load.
Time Converter
Convert between time units including seconds, minutes, hours, days, weeks, months, and years with precise decimal results.
Diff Checker
Compares two input texts side-by-side, highlighting inserted, deleted, and changed lines with distinct background colors.
Regex Tester
Provides an interactive environment where users can write a regular expression pattern, test it against sample strings, and view real-time match.
JSON Formatter
Pretty-prints raw JSON with configurable indent width, key sorting, and bracket collapsing options while flagging syntax errors with exact.
JS Minifier
Strips comments, whitespace, and shortens local variable names in JavaScript source without altering execution semantics.
Base64 Encode/Decode
Encodes text or small files into Base64 strings and decodes them back with automatic MIME-type detection for binary safety.