(PECL solr >= 0.9.2)
SolrQuery::getFacetDateStart — Returns the lower bound for the first date range for all date faceting on this field
$field_override = ?): stringReturns the lower bound for the first date range for all date faceting on this field. Accepts an optional field override
field_overrideThe name of the field
Returns a string on success and null if not set