# Date Expressions

There are several ways to specify the start and end of the selection interval (start-time and end-time settings):

• Literal date value:

  start-time = 2016-06-09 00:00:00
  

• Calendar keyword:

  start-time = next_hour
  

• Calendar expression:

  <base_time> +|- <interval-count> * <interval-unit> [ +|- <interval-count> * <interval-unit> ]
  

  where base_time is specified as literal date or calendar keyword.

  start-time = 2019-12-02 + 18 * hour
  start-time = current_working_day + 18 * hour + 10 * minute
  

The expression is evaluated based on the timezone setting. If the time zone is not explicitly set, the browser time zone is used.