Chrono Calc (Date & Time Calculator) is an intuitive date, time, and duration calculator that lets you perform time-based math just like using a standard calculator.

Whether you need to know "What is the exact date and time 3 days and 5 hours from now?", "How much time has elapsed between two timestamps?", or "How long will a 2-hour 30-minute task take if repeated 3 times?", Chrono Calc gives you instant, accurate answers with a clean and simple interface.

■ Versatile Date & Time Calculations
• Date & Time ± Duration: Add or subtract durations from a starting date/time to find your target timestamp.
Example: 2026/08/06 10:00 + 3d 5h = 2026/08/09 15:00:00
• Date & Time – Date & Time: Calculate the exact elapsed duration or difference between two dates/times.
Example: 2026/08/09 15:00 – 2026/08/06 10:00 = 3d 5h
• Duration ± Duration: Combine or subtract multiple durations to get total or remaining time.
Example: 2d 5h + 3d 10h – 1d 2h = 4d 13h
• Duration × Number: Multiply a duration by a scalar for repeated tasks or schedules.
Example: 2h 30m × 3 = 7h 30m
• Duration ÷ Number: Divide a total duration into equal parts.
Example: 10h ÷ 3 = 3h 20m
• Duration ÷ Duration: Find out how many times a duration fits into a given timeframe.
Example: 10h ÷ 3h = 3.33

■ Fast Input & One-Tap Unit Conversion
• "NOW" Button: Insert the current date and time (down to the second) or today's date with a single tap. Entering time only automatically defaults to today's date.
• Unit Conversion Dropdown: Instantly switch your calculation result between Standard (d/h/m/s), Total Hours (h), Total Days (d), and Total Seconds (s).
• Calculation History: Past calculations are saved automatically. Tap any history item to reload its expression directly back into the calculator.

■ Customizable to Fit Your Style
• 6 Color Themes: Choose from Emerald Forest, Ocean Blue, Sunset Glow, Royal Lavender, Lemon Electric, and Sakura Blossom.
• Dark Mode & Dynamic Color: Full support for Dark Mode and Material You wallpaper-based colors.
• Flexible Date Formats: Switch between YYYY/MM/DD, MM/DD/YYYY, and DD/MM/YYYY to match your region.
• Keep Screen On: Optional setting to prevent your screen from turning off while working.

■ Upgrade to Pro (One-Time Purchase) for Power Features
• Business Day Calculation & Custom Holidays: Register up to 50 custom holiday rules (weekly days off, specific dates/ranges, or Nth weekday of every month) and convert durations into actual working business days.
• Remainder Calculation: View exact quotients and remaining time fractions when dividing durations (e.g., 10h ÷ 7 = 1h 25m 42s (rem. 6s)).
• Expanded History, Memos & Pinning: Expand your history limit up to 100 entries (20 on Free), attach memos (up to 50 chars) to each result, and pin important entries to protect them from bulk deletion.
• Data Backup & Restore: Easily export and restore your settings, custom holidays, and calculation history.
• Completely Ad-Free: Enjoy a distraction-free workspace with no advertisements.

■ Perfect For
• Project management, work-hour estimation, and deadline planning
• Timesheet tracking, shift scheduling, and overtime calculation
• Video, audio, and podcast runtime or editing calculations
• Counting down days and hours to upcoming events or milestones