rscalendar

rscalendar is a small Rust CLI for viewing and changing Google Calendar events.

The first version is intentionally CLI-first. It talks directly to the Google Calendar REST API and uses a bearer token supplied through an environment variable instead of implementing OAuth login inside the app.

Requirements

• Rust toolchain
• A Google OAuth access token with permission to manage calendar events

Export the token before running the app:

export GOOGLE_CALENDAR_ACCESS_TOKEN="your-access-token"

Build, test, and lint

Build the application:

cargo build

Run the full test suite:

cargo test

Run a single test:

cargo test parses_rfc3339_time

Format the code:

cargo fmt

Check formatting without rewriting files:

cargo fmt --check

Run Clippy:

cargo clippy --all-targets --all-features -- -D warnings

Usage

Show the built-in CLI help:

cargo run -- --help

List upcoming events from the primary calendar:

cargo run -- list --max-results 5

Create a timed event:

cargo run -- create \
  --summary "Design review" \
  --start "2026-03-25T09:00:00+02:00" \
  --end "2026-03-25T10:00:00+02:00" \
  --location "Room 101"

Create an all-day event:

cargo run -- create \
  --summary "Vacation" \
  --start "2026-04-10" \
  --end "2026-04-12"

For all-day events, the CLI treats the --end date as inclusive and converts it to Google Calendar's exclusive end-date format.

Update an event:

cargo run -- update \
  --event-id "event-id" \
  --summary "Updated title"

Delete an event:

cargo run -- delete --event-id "event-id"

Use a non-primary calendar by adding --calendar-id.

Architecture

The app currently lives in a single binary crate:

• src/main.rs contains the CLI definitions, the Google Calendar HTTP client, request payload helpers, and unit tests for date parsing and sparse patch generation.
• clap handles command parsing.
• reqwest performs authenticated REST calls.
• serde and serde_json map Google Calendar request and response payloads.
• chrono parses RFC3339 timestamps and date-only all-day events.

This version supports four operations:

• list for upcoming events
• create for inserting events
• update for patching selected event fields
• delete for removing events