Nobody wants to answer this ! Where are all our chancery lawyers? LOL
How much detail do you want (believe me, it's tedious).All these provisions are destined to make life easier for executors,in particular where the will creates a trust or gift such as "to X for life, remainder to Y" or 'to X if he attains the age of 25" [and X does]. The first appears,particularly, to enable the executors to deal with specific bequests of money ( �1,000 say)where the residue of the estate would raise the sum easily enough but the deceased has not left enough in his bank account or in cash to pay the sum.The last is,inter alia, to avoid a whole lot of , usually petty, calculations, if, say, the will creates a trust whereby X is entitled only if he attains ,say, 25 years or a trust whereby X holds for life, then to Y and X dies in the middle of a quarter.It also means that executors can deal with annual income arising from a policy of assurance (which, curiously, the 1870 Act excluded) The middle one, likewise, seems destined to simplify life.There may well be other examples, but it's conceivable that a beneficiary of income was entitled to it only up to his death. On his death, dividends and other income from the trust of which he had been the beneficiary will still be coming in. To avoid any arguments, it's easier to treat that income as all arising after death, rather than,for example, faff about trying to work out how many days of a quarterly or annual income were before or after death, and then proceed to deal with the whole lot in accordance with whatever terms of any trust or otherwise apply.