Datetime fields cannot be used in the where-clause

[Piiit]

https://mobility.api.opendatahub.bz.it/v2/flat/MeteoStation/*/latest?limit=-1&where=tname.eq.precipitation,mvalidtime.gt.2016-07-13T16:20:40.861

gives

{
  "code": 400,
  "message": "SELECT EXPANSION ERROR: Syntax Error in WHERE clause: Operator 'GT.<STRING>' does not exist",
  "error": "Bad Request",
  "timestamp": 1618842668622
}