Tex. Code of Criminal Procedure § 43.13

(a) A defendant who has remained in jail the length of time required by the judgment and sentence shall be discharged. The sheriff shall return the copy of the judgment and sentence, or the capias under which the defendant was imprisoned, to the proper court, stating how it was executed.

(b) A defendant convicted of a misdemeanor and sentenced to a term of confinement discharges the defendant's sentence at any time beginning at 6 a.m. and ending at 5 p.m. on the day of discharge.

(c) Except as provided by Subsections (d) and (e), the sheriff or other county jail administrator shall release a defendant at any time beginning at 6 a.m. and ending at 5 p.m. on the day the defendant discharges the defendant's sentence.

(d) The sheriff or other county jail administrator may:

(1) credit a defendant with not more than 18 hours of time served; and

(2) release the defendant at any time beginning at 6 a.m. and ending at 5 p.m. on the day preceding the day on which the defendant discharges the defendant's sentence.

(e) A sheriff or other county jail administrator may release a defendant from county jail after 5 p.m. and before 6 a.m. if the defendant:

(1) agrees to or requests a release after 5 p.m. and before 6 a.m.;

(2) is subject to an arrest warrant issued by another county and is being released for purposes of executing that arrest warrant;

(3) is being transferred to the custody of another state, a unit of the federal government, or a facility operated by or under contract with the Texas Department of Criminal Justice; or

(4) is being admitted to an inpatient mental health facility or a state supported living center for court-ordered mental health or intellectual disability services.