Tex. Government Code § 24.029

(a) If by an amendment to this chapter a county is removed from the composition of an existing judicial district and added to another existing or new judicial district, or if an amendment to this chapter changes the time or place at which the terms of court are held, all processes, writs, bonds, recognizances, and other obligations issued from and made returnable to that court before the effective date of the transfer or other change are returnable as provided by this subsection. An obligation issued from the affected court is returnable to another district court in the county on the date that court directs, but may not be made returnable on a date that is earlier than the date on which the obligation was originally returnable. The obligations are legal and valid as if the obligations had been made returnable to the issuing court.

(b) The obligees in all appearance bonds and recognizances taken in and for a district court of a county before the effective date of an amendment to this chapter, and all witnesses summoned to appear before that district court under laws existing before the effective date of an amendment to this chapter, are required to appear at another district court in the county on the date that court directs, but may not be required to appear on a date that is earlier than the date on which the obligees or witnesses were originally required to appear.