"The term a calendar month is a legal and technical term … . The meaning of the phrase is that, in computing time by calendar months, the time must be reckoned by looking at the calendar and not by counting days; and that one calendar month's imprisonment is to be calculated from the day of imprisonment to the day numerically corresponding to that day in the following month less one."
"42 If there is ambiguity in Immigration Rules and the Secretary of State publicly declares that he/she will adopt the more lenient interpretation, then tribunals and courts may hold the Secretary of State to that assurance. This is exemplified by the Court of Appeal's decision in Adeyodin v Secretary of State for the Home Department[2010] EWCA Civ 773 … At paragraph 70 Rix LJ said that in a situation of genuine ambiguity, it was legitimate to derive assistance from the executive's formally published guidance, including IDIs 43. I would respectfully agree with paragraph 70 of Rix LJ's judgment in Adeyodin. I would, however, add this comment. I do not think it is possible for the Secretary of State to rely upon extraneous material in order to persuade a court or tribunal to construe the rules more harshly or to resolve an ambiguity in the Government's favour. The Secretary of State holds all the cards. The Secretary of State drafts the rules; the Secretary of State issues the IDIs and guidance statements; the Secretary of State authorises the public statements made by his/her officials. The Secretary of State cannot toughen up the rules otherwise than by making formal amendments and laying them before Parliament. That follows from the Supreme Court's reasoning in R (Alvi) v Secretary of State for the Home Department[2012] UKSC 33 …"