Task mutations — new optional iana timezone field

Summary

The createTask and updateTask GraphQL mutations now accept an optional iana field. When provided, this IANA timezone identifier (e.g. "Europe/Paris") is used to convert the task's UTC due date into the correct local time before it appears in email notifications.

Previously, due dates in task emails were formatted in UTC, which could show the wrong calendar date for recipients in non-UTC timezones (for example, a due date of midnight Paris time would appear as the previous day in the email). This field resolves that.

Integration guidance

• iana is optional. Existing integrations that do not send this field continue to work as before.
• Pass a valid IANA timezone string that reflects the timezone of the task's assignee or practice, for example "Europe/London" or "America/New_York".
• If omitted, the fallback sequence is: practice's configured timezone (settings.general.timezone) → UTC as a last resort.

Affected mutations

Mutation	New field
createTask	iana: String (optional)
updateTask	iana: String (optional)

Example

mutation {
  createTask(input: {
    subject: "Follow-up consultation"
    dueDate: "2026-06-01T22:00:00.000Z"
    iana: "Europe/Paris"
    priority: High
  }) {
    id
  }
}

The above will display the due date as 2 June 2026 in the notification email for a Paris-timezone recipient, rather than 1 June.

If something breaks after this change

This is a purely additive change. No existing field has been removed or renamed. If you experience unexpected behaviour, verify that the iana value you pass is a valid IANA timezone string.