: Try solr.TrieDateField instead and note the docs on the "ms" function, from the same wiki page you linked to...
>> Arguments may be numerically indexed date fields such as TrieDate >> (recommended field type for dates since Solr 1.4), or date math >> (examples in SolrQuerySyntax) based on a constant date or NOW. >> >> Things other than these will _not_ work as arguments. For example, you >> cannot currently use: >> * "classic", non-numerically indexed date fields (i.e. fields backed >> by DateField or LegacyDateField classes) >> * other functions (e.g. map, sum, etc.) -Hoss
