# Timer#

Timer provides the time at which the Timer callback timeout and related information.

A simplified sequence diagram focusing only on the relevant events is shown below.

to_dataframe API returns a table which has the following columns.

Column Type Description
timer_event_timestamp System time Timer timeout.
callback_start_timestamp System time Callback start time
callback_end_timestamp System time Callback end time

Here, the timer firing time is calculated by the following,

t_{timeout} = t_{init} + n \times t_{period}