Free Calendar Tools
Free online calendar tools for date calculations, calendar generation, and event planning. Calculate business days, create custom calendars, convert time zones — all in your browser.
Available Tools
Academic Calendar Maker
Create custom academic calendars with semesters and holidays
Advent Calendar Creator
Design personalized Advent calendars for the holiday season
Business Hours Calculator
Calculate working hours between dates excluding weekends and holidays
Calendar Matrix Generator
Generate calendar grids and matrices for any year
Calendar RSS Generator
Create RSS feeds from calendar events for subscriptions
Calendar Sync Overlay
Merge and overlay multiple calendar sources
Date Picker Generator
Create embeddable date picker components
Event Countdown
Create countdown timers to specific events or dates
Fiscal Year Calendar
Generate fiscal year calendars for business planning
Hijri Calendar Converter
Convert between Gregorian and Islamic Hijri calendar dates
Moon Phase Calendar
Display moon phases for any month or year
Online Calendar Holidays
Browse and add public holidays from countries worldwide
Payday Calculator
Calculate paydates based on pay frequency and start date
Perpetual Calendar
View any date from any year with day of week
Pregnancy Due Date Calendar
Calculate due dates and track pregnancy milestones
Printable Calendar Maker
Design and print custom calendars in various formats
Seasonal Calendar
View astronomical and meteorological season dates
Need More Date Tools?
Check out our date-time tools for more date utilities, or explore all available tools.
What These Calendar Tools Do
This is a collection of 17 free calendar tools that run entirely in your browser. No software installation, no subscriptions, no waiting. You pick a date or upload events, click a button, and get results instantly.
The tools cover four main workflows: calculating dates and durations (add days, find business hours, calculate paydays), generating calendars (printable, academic, fiscal year, moon phases), converting between systems (time zones, Hijri calendar), and planning events (countdowns, holiday calendars, sync overlays).
How to Use These Tools
Most tools follow the same pattern:
- Select a date using the picker or enter manually
- Choose your calculation or output format
- Adjust settings like holidays, weekends, or time zones
- View results, print, or download as PDF/ICS
Everything happens client-side using JavaScript. Your calendar data stays in your browser tab and never touches any server.
Who Uses These Tools
Project managers calculate business days between milestones, generate Gantt-style fiscal calendars, or plan around international holidays for distributed teams.
HR and payroll teams compute paydates for biweekly or monthly schedules, track employee vacation days, or generate onboarding calendars for new hires.
Teachers and administrators create academic calendars with semester dates, plan around school holidays, or generate printable calendars for classroom use.
Event planners build countdown timers for weddings or conferences, check moon phases for outdoor events, or overlay multiple calendar sources for venue scheduling.
Tool Categories
Date Calculations
Date Calculator adds or subtracts days, weeks, months, and years. Business Hours Calculator counts working days excluding weekends and holidays. Week Number Calculator returns the ISO 8601 week number. Payday Calculator projects paydates based on frequency.
Calendar Generation
Printable Calendar Maker produces PDFs in monthly, weekly, or yearly formats. Academic Calendar Maker builds semester-based calendars. Fiscal Year Calendar generates business year views. Moon Phase Calendar displays lunar cycles. Advent Calendar Creator designs holiday countdowns.
Time and Zone Conversion
Time Zone Converter translates times between geographic zones. Hijri Calendar Converter maps Gregorian dates to Islamic lunar calendar dates. Seasonal Calendar shows equinox and solstice dates.
Event Planning
Event Countdown creates timers to target dates. Online Calendar Holidays browses public holidays by country. Calendar RSS Generator produces subscribable event feeds. Calendar Sync Overlay merges multiple calendar sources.
Specialized Calendars
Pregnancy Due Date Calendar tracks gestation milestones. Perpetual Calendar displays any historical or future date. Calendar Matrix Generator produces grid layouts for custom applications. Date Picker Generator creates embeddable calendar widgets.
Limitations and Gotchas
Holiday data: Holiday calendars are provided as reference only. Official holiday dates vary by jurisdiction and may change.
Time zones: DST transitions can shift UTC offsets. Always verify times near DST boundaries.
Hijri calendar: Islamic calendar dates depend on moon sightings and vary by region. Conversions are approximate.
Print formatting: Browser print settings affect output. Use landscape orientation for wide calendars and check "background graphics" for colors.
Why 1000freetools
Calendar software often means buying expensive subscriptions or wrestling with bloated productivity suites. But sometimes you just need to know what date it will be in 90 days, print a calendar for your classroom, or check if a date falls on a bank holiday. These tools exist because calendar math shouldn't require a PhD or a credit card. Everything runs in your browser — no account, no sync, no upsells.