When2Meet Scheduling

When2Meet Scheduling

Programmatically create When2Meet events and pre-fill participant availability using When2Meet's reverse-engineered HTTP API. This avoids manual data entry when organizers already know some participants' schedules.

When to Use

• Creating a When2Meet event from the command line
• Pre-filling known availability for instructors, organizers, or team leads
• Automating recurring scheduling polls
• Any scenario where a When2Meet link needs participants' times baked in

Core Workflow

1. Gather Requirements

Before writing any code, collect from the user:

Parameter	Example
Event name	"Project Meeting Sign-Up"
Dates (specific)	Feb 9, 11, 12, 13 2026
Time window	10:00 AM to 6:00 PM
Timezone	America/Los_Angeles
Participants + availability	Keith: Mon 11-11:30, Wed 10-10:45...

2. Create the Event

POST multipart form data to https://www.when2meet.com/SaveNewEvent.php.

Key fields: NewEventName, DateTypes ("SpecificDates"), PossibleDates (pipe-delimited YYYY-MM-DD), NoEarlierThan / NoLaterThan (hours 0-23), TimeZone (IANA name).

The response HTML contains window.location='./?SLUG' with the event slug. Normalize the relative path (strip leading ./) to build the full URL.

3. Fetch Slot Timestamps

GET the event page at https://www.when2meet.com/?SLUG. Parse TimeOfSlot[n]=<unix_timestamp>; from the embedded JavaScript. These timestamps are the canonical slot IDs; never compute them manually.

4. Login Each Participant

POST to https://www.when2meet.com/ProcessLogin.php with id (numeric event ID), name, password ("" for open events), and _ (""). The response body is the plain-text person ID.

5. Save Availability

POST to https://www.when2meet.com/SaveTimes.php. Critical: send ALL event slots in the slots field (each timestamp followed by %), with a positional availability string of 0s and 1s marking which slots are available. The server uses position-based mapping, so sending only available slots will misalign the data.

Fields: person, event, slots, availability, _ ("").

Critical Gotchas

1. Send ALL slots, not just available ones. SaveTimes.php maps the availability string positionally against the full slot list. Sending a subset causes silent misalignment.
2. Event creation uses multipart/form-data, not URL-encoded. In Python requests, use files= parameter with (None, value) tuples.
3. Dates are pipe-delimited YYYY-MM-DD strings, not Unix timestamps.
4. The redirect path is relative (e.g. ./?34954911-FtY36). Strip the ./ prefix before constructing the full URL.
5. No cookies or sessions needed. The person ID from login is the sole auth token for saving availability.
6. Timezone awareness: Always fetch TimeOfSlot values from the server rather than computing timestamps manually. The server handles timezone conversion when the event specifies a TimeZone field.

Ready-to-Run Script

A complete, tested Python script is available at:

scripts/when2meet_setup.py

To customize for a new event, edit the configuration block at the top of the script: EVENT_NAME, DATES, NO_EARLIER_THAN, NO_LATER_THAN, TIMEZONE, and the PARTICIPANTS dictionary.

Run with: python scripts/when2meet_setup.py (requires requests in a venv).

Additional Resources

Reference Files

• references/api-reference.md: Complete When2Meet API documentation with all endpoints, field formats, response parsing, and slot timestamp details

Scripts

• scripts/when2meet_setup.py: Full working script for creating events and pre-filling availability. Edit the config block and run.