When will Prince Charles overtake Edward VII as the longest serving Prince of Wales The article states under the Section Youth Subsection Created Prince of Wales that Charles is the oldest Prince of Wales since it became the title granted to the heir apparent to the English throne and the third longest serving Prince of Wales behind George IV and Edward VII whom he will pass on 10 October 2017 Is this date correct Edward VII s tenure as Prince of Wales lasted from 8 December 1841 to 22 January 1901 a period of 59 years and 45 days Charles was created Prince of Wales on 26 July 1958 and 59 years and 45 days from that date will be 10 September 2017 so that should be the date on which Charles will overtake Edward VII as the longest serving Prince of Wales and not 10 October 2017 as the article currently states 82 26 7 221 talk Corrected I changed the other day too as that also seemed out DrKiernan talk But 26 July 1958 21594 days brings you to 8 September 2017 so that s the day they d be equal and 9 September 2017 would be the day Charles exceeds Edward Nunh huh I have changed the date Charles would exceed the age William IV was when he assumed the throne to 20 September 2013 on also as it had previously said on there as well that this date would be 18 September 2013 For consistency not sure if any other pages would need updating likewise With regards to the date that Charles would overtake Edward VII as the longest serving Prince of Wales 59 years from 26 July 1958 would be 26 July 2017 then it would be 5 days to the end of July then add the 31 days in August and then 9 days in September to give 9 September as the date they would be equal since 5 31 9 45 and hence 10 September as the earliest date Charles would have overtaken Edward VII s record unsigned If you want an accurate date you need to calculate in days not years because all years are not the same some have 365 days and others have 366 days You d apparently say 8 December 1841 and 8 December 1900 are exactly 59 years apart but in fact they are 59x365 14 21549 days apart For the actual dates involved 8 December 1841 21594 days 22 January 1901 26 July 1958 21594 days 8 September 2017 Nunh huh For this calculation between 8 December 1841 and 8 December 1900 there were 59 years i e 59x365 21535 days and also 15 extra days taking the leap years into account i e 29 February for each of 1844 1848 1852 1856 1860 1864 1868 1872 1876 1880 1884 1888 1892 1896 1900 to give 21550 plus 45 days to give 21595 days in total so they would be equal on 9 September and Charles would exceed Edward VII s record on 10 September This can also be confirmed with Excel or other such software Subtracting 08 12 1841 from 22 01 1901 gives 21595 days and adding 21595 days to 26 07 1958 gives 09 09 2017 as the day they would be equal and 10 September as the first day Charles could claim to have exceeded Edward VII s record unsigned 1900 was not a leap year If Excel is telling you it is you should return it for a refund Nunh huh Actually forget that they ll never give you your money back It s a known bug in Excel see Suffice it to say that Excel is pretty much useless for historical dates Nunh huh I m going to take silence as the absence of further objection I will change the article so that it gives the correct date 9 September 2017 as the date when Charles would become the longest serving Prince of Wales I ve also calculated the correct date for when he would surpass the age of William IV on assuming the throne William IV was born 21 August 1765 and assumed the throne on his father s death on 26 June 1830 Thus he was 26 June 1830 minus 21 August 1765 or 23684 days old Charles was born 14 November 1948 If we add 23684 days to that we would get 18 September 2013 the date on which he would equal the age at which William IV ascended the throne and 19 September 2013 as the date on which he would exceed it I will change the article accordingly Nunh huh Yes please do take silence as the absence of further objection I have also changed the date Charles would exceed the age William IV was when he assumed the throne to 19 September 2013 on for consistency as it had previously said 20 September 2013 on there However when will the reign of the current monarch Elizabeth II exceed that of Queen Victoria This web page