From Dashboard settings, click the Timepicker tab. From here you can specify the relative and auto refresh intervals. The Timepicker tab settings are saved on a per Dashboard basis. Entries are comma separated and accept a number followed by one of the following units: `s (seconds)`, `m (minutes)`, `h (hours)`, `d (days)`, `w (weeks)`, `M (months)`, `y (years)`.
In Grafana v2.x you can now override the relative time range for individual panels, causing them to be different than what is selected in the Dashboard time picker in the upper right. You can also add a time shift to individual panels. This allows you to show metrics from different time periods or days at the same time.
When you zoom or change the Dashboard time to a custom absolute time range, all panel overrides will be disabled. The panel relative time override is only active when the dashboard time is also relative. The panel timeshift override however is always active, even when the dashboard time is absolute.
The `Hide time override info` option allows you to hide the the override info text that is by default shown in the
upper right of a panel when overridden time range options.
Currently you can only override the dashboard time with relative time ranges, not absolute time ranges.