tcalc

A CLI for time arithmetic. Inspired by when. Try it online.

Examples:

• 2023/12/25 - 7d → subtracts 7 days from December 25, 2023
• 2am + 30m → adds 30 minutes to 2:00 AM
• today - 2025/12/25 -> days until December 25, 2025

Usage

Run without installing: cargo run -p cli -- "2am + 30m"

Syntax

• Dates use YYYY/MM/DD and can include time as YYYY/MM/DD HH:MM.
• Times accept 24-hour HH:MM or H[am|pm] forms (2pm → 14:00).
• Keywords: today, tomorrow, yesterday, now.
• Durations combine a number with a unit: y, year, month, day|d, hour|h, minute|m, second|s.
• Combine values with + and -, chaining operations left-to-right (today - 2h + 30m).