(1) The punishment of imprisonment or detention which is not postponed in accordance with the provision of section 151 or suspended shall begin to run on the day on which the warrant is formally read but if the offender has been kept in custody since the date on which warrant was signed by the officer who tried him, the sentence shall begin to run on that date.
(2) Other punishments shall take effect on the date on which the warrant is formally read.
(3) Notwithstanding that the state of health of the offender is such as renders him unable to under-go the whole or any part of the summary punishment to which he may have rendered himself liable and it appears probable that he will be invalided from the service or remain for a considerable time unfit for punishment, the punishment merited for his offence shall be awarded and should it require a warrant, it is to be completed and duly signed and read if necessary in the absence of the accused in order that he may not escape the consequences of the punishment such as loss of pay or stoppage of leave.