The style of all writs and process shall be “The State of Texas;” and unless otherwise specially provided by law or these rules every such writ and process shall be directed to any sheriff or any constable within the State of Texas, shall be made returnable on the Monday next after expiration of twenty days from the date of service thereof, and shall be dated and attested by the clerk with the seal of the court impressed thereon; and the date of issuance shall be noted thereon.