In her third year at Hogwarts, Hermione is given a time-turner so she can take more classes. Several of her classes are concurrent to each other, so she attends one class (for 1-2 hours) goes back in time, and attends a different class during the same time frame.

But from an aging point of view, she should age 4 hours in relation to the 2 hours everyone else ages. How much older should Hermione be relative to everyone else after using the time-turner for an entire school year?

  • 10
    great observation, i must add. never thought about it meself. May 24, 2012 at 10:31
  • Note that Hermione has already started out as one of the oldest in her classes, being almost 12 years old when he started Hogwarts.
    – b_jonas
    Sep 10, 2012 at 15:07
  • @ManikSethisuwan me neither. Jul 27, 2015 at 3:42
  • 9
    Curious thought: by the same argument, after her petrification in her second year would she not be several months younger? While petrified she didn't need to eat, or sleep, can we assume she didn't age either?
    – Cooper
    Mar 21, 2017 at 21:24
  • 2
    Oh I am older now Oct 17, 2018 at 17:54

3 Answers 3


For those of you who aren't going to make it to the end of this post, it comes out to a week (plus half a day).

It is not certain whether wizards using time turners "age" faster, but for the sake of the question let's assume so and see if we can quantify somewhat.

According to the Harry Potter Wiki, there are 12 classes she could have been taking (7 core, 5 elective), and she signed up for all of them (Chamber of Secrets, first American edition, p.252). Assume she was allowed to take all of them (reasonable, I think). After dropping two classes (Divination and Muggle Studies), Hermione was able to resume a normal schedule. We'll take that as showing that ten courses fills the time allotted for classes completely. Let's say that's six hours a day, five days a week. That would make three hours per class per week; the two extra classes would then add six hours a week to Hermione's age. We'll assume she didn't use the TT for extra studying time on top of that (though I'm not quite certain of that).

The students arrived at school on September 1st as always, and Hermione dropped Divination around Easter. I didn't quickly find the event in the book, so we'll assume it was Easter (April 3, 1994). Now, if I counted right on my calendar, that's 29 weeks for Divination. The Christmas holidays remove two weeks from that, and we'll say another week for reading and exam period, so we'll say 26 weeks for three hours a week, making the added time from Divination three days and six hours.

She continued Muggle Studies through the end of the year. The wiki page says that's in the third week of June, for a total of 40 weeks (again assuming I counted correctly). Take out the three weeks off before Easter, and another two for reading, exams, and results, for a total of 35 weeks doubling for Muggle Studies another three hours a week. This comes out to four days and three hours.

Adding this to the Divination time and the three hours she and Harry spent saving Sirius and Buckbeak, we get seven days, twelve hours. Therefore, the answer appears to be just over a week.

  • 11
    So basically, an old hag :) Nov 20, 2011 at 1:16
  • 42
    I applaud you for this impressive display of research skills and logical thinking. +1 from me.
    – sbi
    Nov 20, 2011 at 7:38
  • 13
    A time-turner would be cool in real life. Just combine it with a time-skipper. Use the time-skipper on flights, collect the hours, and use them in the mornings to sleep longer. Double benefit and no time lost. Nov 20, 2011 at 13:23
  • 9
    @AndrewJ.Brehm You can store up wakefulness and speed with Feruchemy, though that's from a different fantasy world altogether. ;)
    – kojiro
    Nov 21, 2011 at 16:07
  • 20
    @user8723 People who berate others for writing Divination wrong and then go on to write Professor McGonagall’s name as “Magonagle”… *sigh* Jul 21, 2015 at 8:51

Hermione might also have reserved extra time for studying and additional sleep. So while the lower bound is, as Kevin says, 7.5 days, assuming she did not use her time turner over the holidays, she could have aged up to 32 hours per day. This potentially includes weekends (assuming that Hermione, often a stickler for rules, had permission to use the device so).

Assuming, then, there are 35 weeks of classes, we have an upper bound of 1470 hours, or about 60 days.

If, on the other hand, Hermione abused her time turner by using it during the holidays, we get as high as 70 days.

I have read some fan fiction that interpreted the restrictions on time turner usage as allowing one to go back six hours at a time, up to six times per day, for a total of an additional 36 hours per day. I think it's more straightforward to interpret each spin of the time turner as one use, for a total of six hours added per day. However, if this interpretation is correct, Hermione could have aged 460 days (and needed a second bed).


We are not told exactly how many classes she doubles up on, or how long they are, or how long the terms are, so a definitive answer is not really possible.

If it was one 2 hour class, 13 weeks a term, 2.5 terms, that would be 65 hours - 3 and a bit days. Even if these figures are out, it is liable to be a week older, not much more.

  • 1
    At the end of the book/movie (I forget which if not both), it's said that she dropped Divinity which freed up her schedule to be a normal one. So at most, she would only age 2 extra hours a day (if her classes weren't blocked out to every other day) Nov 19, 2011 at 21:42
  • 9
    @OghmaOsiris: She dropped Divinity? I didn't even know she was related to Jesus! Oh wait, you mean 'divination'? ;)
    – Jeff
    Nov 20, 2011 at 2:18
  • 2
    @oghma I looked it up for my answer. She dropped divination in the spring and then muggle studies after the term ended.
    – Kevin
    Nov 20, 2011 at 2:30

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