"(45) . . . But once the court has decided that credit should be given it should say so, and it would then be entitled to adjourn for appropriate information to be provided about the relevant number of days. In short, if for whatever reason that calculation has not been made, or the court is uncertain about the 'time served', but considers that in principle the time spent in custody should be treated as time served, the court may properly direct that the period will be deducted after the appropriate calculation has been made, and adjourn this part of the process. (46) Thereafter the calculation should be made promptly. Plainly if there is any dispute about it, the arguments should be reduced to writing and put before the sentencing judge for his consideration. If necessary he may order a short further oral hearing . . . We emphasise that the adjournment should be for a limited period only, and the final decision should, save in exceptional circumstances, be concluded within 28 days. But even if delayed beyond that period, it would be permissible for the Crown Court to deal with what is no more than the final implementation of its order. This would not be a variation or rescission of sentence. It would merely represent the conclusion of an adjourned part of the sentencing process . . . (47) . . . We see no reason why the judge cannot use language making clear that he is directing that the defendant should receive credit for the full period of time spent in custody on remand (or any particular part of that period), that on the basis of the information currently before him the relevant period is X days, but if this period proved to be based on an administrative error, on being informed, the court would order an amendment of the record for the correct period to be recorded. Approaching the problem in this way, the number of days to be credited may properly be regarded as a temporary rather than a final order, and therefore open to correction if and when any error emerges. If of course there were any continuing issue about the number of days, the case would have to be re-listed for a judicial decision in open court. Again, the corrected order should be listed and pronounced in open court. Arrangements like these would not fall foul of the 28-day rule."