All Timers are persisted, therefore, if the Node.js session is restared timers will pickup where they left

Timer Types

DateTime (not supported)



Example (interval lasting 10 days):


Time Cycle

Example (3 repeating intervals, each lasting 10 hours):


Time Cycle accepts both ISO 8601 format and Cron format

Example for cron format:

        <bpmn:timeCycle xsi:type="bpmn:tFormalExpression">5 * * * *</bpmn:timeCycle>

Development/Test Environment Timer modification

bpmn-server allow you to modify the timer behaviour during development without changing bpmn definition

By changing the configuration.ts to force timers to specific time

let definitionsPath = __dirname + '/processes/';
var configuration = new Configuration(
        definitionsPath: definitionsPath,
        timers: {
            forceTimersDelay: 1000,
            precision: 3000,

Event Types

Event Type TimeDate Duration TimeCycle TimeCycle Repeat
Start NA NA Yes Default
Intermediate NA Yes Yes NA
Boundary Event NA Yes Yes Yes
  • Start Event support ‘Time Cycle’ only since duration and timeDate make no sense.
  • Intermediate Events are implemented as a normal event, will start the timer at start of the node and once the timer is completed the node will end.
  • Start Event Timers will start a new execution, therefore, they are scheduled by a cron job managed by bpmn-server.


On Server start:

  1. All start event are re-evaluated and reschedules
  2. other events that are in wait state are re-evaluated and reschedules