A mechanism for providing instant messaging (IM) users with an alarm to remind users of an event or to re-join an IM chat. An instant message requesting a user to participate in an event is received at an IM client. If the user cannot participate in the event, the user creates an alarm message defining a delay time period after which the user can participate in the event, which is sent to users in the IM chat session. Responsive to receiving the alarm message at an IM client, a countdown of the delay time period is initiated. Additionally, the receipt of the alarm message and timer countdown processing may occur on the IM server, which dispatches a message to the IM client upon timer expiration. Upon expiration of the timer, an alarm popup window is displayed which reminds the user to participate in the event.