Timer Event

A timer event is an event (start, intermediate, or boundary) with a small clock-face marker. It fires on a time-based rule: a fixed duration after something ("48 hours after the order is placed"), a recurring cycle ("every Monday at 09:00"), or an absolute deadline ("on 2026-12-31 at midnight"). Timer events are the most common kind of non-plain event in real diagrams; delays and deadlines show up everywhere.

Three placements matter. A timer *start* event invokes a new process instance on a schedule: "run the daily reconciliation at 02:00". A timer *intermediate* event pauses the flow for a duration: "wait 5 business days, then send the reminder". A timer *boundary* event on an activity implements a timeout: "if the manager does not respond within 48 hours, escalate". Each is a natural fit for a different modelling need.

• Duration: ISO 8601, e.g. `PT48H` for 48 hours, `P1D` for 1 day, `P2W` for 2 weeks. Use for relative delays.
• Cycle: ISO 8601 recurring, e.g. `R/PT1H` (every hour), or cron-like depending on engine. Use for recurring starts.
• Date: ISO 8601 instant, e.g. `2026-12-31T23:59:00Z`. Use for one-time deadlines.
• Expression: a dynamic value computed from process data, e.g. "three business days after `order.date`". Supported on most engines.

LucidFlow classifies timer mentions in source documents: "wait 48 hours" becomes an intermediate timer with duration PT48H, "if no response within 3 days" on the boundary of an activity becomes a timer boundary event, "every Monday at 9am" attached to a start becomes a timer start. The cost dashboard attributes timer wait time to the appropriate nodes: an intermediate timer contributes to the instance elapsed duration but not to work cost, a boundary timer rarely fires so its contribution is typically small but sharp when it does.