- filtertype: period  source: name  range_from: -1  range_to: -1  timestring: '%Y.%m.%d'  unit: days

range_from and range_to are counters of wholeunits. A negative number indicates a whole unit in the past, while a positive number indicates a whole unit in the future. A0 indicates the present unit.

Read more about this setting in context in theperiod filtertype documentation, including examples.