Provided are a computer program product, system, and method for setting timers based on processing of communications using natural language processing. A communication is detected from a communicating participant transmitted within a group communication session implemented in a computer network in which the communicating participant is communicating with an additional participant through the group communication session. A natural language processor (NLP) module processes the detected communication to determine words comprising an expressed temporal commitment of the communicating participant. The expressed temporal commitment does not express a computer implemented command verb to perform an operation related to setting a time variable. A timer is set, in a computer user interface of the additional participant, to a time value based on the expressed temporal commitment in the detected communication.