How to use the command 'calendar' (with examples)

The calendar command is a powerful utility for users who want to keep track of important dates and events efficiently. It reads through a specified calendar file (or default system-provided calendars) and displays upcoming dates and corresponding events. This tool is especially useful for users who need a quick look into their schedule without opening complex calendar applications.

Use case 1: Show events for today and tomorrow (or the weekend on Friday) from the default calendar

Code:

calendar

Motivation:

Using the calendar command without any additional flags is the simplest form of its usage. This is perfect for users who want a quick glance at their immediate schedule. Whether you are planning your day or preparing for the weekend, a single command gives you all the necessary information at a glance.

Explanation:

When the command calendar is run without any flags, it defaults to showing events for today and the following day. If today is a Friday, it extends its preview to include events for the upcoming weekend. This behavior aligns with typical work and school week structures, ensuring users are prepared for both weekday and weekend events.

Example output:

Apr 20  Event for Today
Apr 21  Task Due Tomorrow
Apr 22  Weekend Family Gathering

Use case 2: Look [A]head, showing events for the next 30 days

Code:

calendar -A 30

Motivation:

The calendar -A 30 command allows users to plan further ahead than just the next couple of days. This is particularly useful for those responsible for managing longer-term projects or planning vacations, as it gives a broad overview of upcoming events and commitments up to a month in advance.

Explanation:

The -A 30 flag tells the calendar command to include all events happening in the next 30 days in its output. The ‘A’ stands for ‘Ahead,’ which naturally aligns with the concept of looking forward or planning ahead. Users can customize the number of days according to their planning horizon by replacing ‘30’ with any number they desire.

Example output:

Apr 22  Weekend Family Gathering
Apr 25  Project Deadline
May 05  Conference
May 18  Anniversary Celebration

Use case 3: Look [B]ack, showing events for the previous 7 days

Code:

calendar -B 7

Motivation:

For individuals or teams interested in reviewing past events, using the calendar -B 7 command can be very beneficial. Whether the purpose is to create reports, write retrospectives, or simply reflect on past activities, this command provides a comprehensive reverse glance into the prior week’s schedule.

Explanation:

The -B 7 flag instructs the calendar command to output events from the past 7 days. The ‘B’ stands for ‘Back,’ which is indicative of the command’s function to retrieve past events. By specifying ‘7’, users choose to see a complete week’s worth of history, which is often an ideal timeframe for monitoring purposes.

Example output:

Apr 13  Board Meeting
Apr 15  Team Lunch
Apr 19  Tax Filing Deadline

Use case 4: Show events from a custom calendar [f]ile

Code:

calendar -f path/to/file

Motivation:

Not every user will find the default calendar sufficient, especially if they have specific project deadlines or personal commitments not covered. The ability to specify a custom calendar file using calendar -f path/to/file is advantageous for tailoring the calendar output to suit individual or organizational needs.

Explanation:

The -f option allows users to point the calendar command to a specific file path, overriding the default location. ‘f’ stands for ‘file,’ which makes it intuitive to remember. When users denote path/to/file, they must replace this placeholder with the actual path to their customized calendar file, thereby enabling the command to fetch and show events from that specific source.

Example output:

Custom Events:
Apr 23  John's Birthday
Apr 26  Tailor Appointment
Apr 30  Project X Review

Conclusion:

The calendar command, with its range of flags and functionalities, empowers users to manage and review their schedules efficiently in a command-line environment. From showing today’s events to examining past and future timelines, or even consulting customized calendar files tailored to specific needs, this command offers a versatile and time-efficient solution for managing personal and professional time commitments. Whether you’re scheduling short-term activities or planning for the long-term, the calendar command helps you stay organized with minimal fuss.