With apologies for the attention-grabbing title: of course I am not actually asking you to tell me when I, specifically, should schedule my defense. But I have heard very plausible-sounding rumors that the time of day at which a PhD candidate holds their thesis defense can have an impact on the difficulty and even the candidate's chance of passing. For example, scheduling a defense just before lunch may mean the committee will ask fewer and less involved questions, because they will be anxious to finish so they can go eat. Similarly defending in the mid afternoon may lead to less complex questions because everyone is tired - or alternatively it could cause a more difficult defense because the committee members are in no hurry to get back to work. And so on; the rumors abound.

What I would like to know: is there is any research backing up the idea that there are better or worse times of day for a candidate to schedule their thesis defense? Any anecdotal experience from people who have sat on multiple PhD committees?

Of course I'm not claiming this should be a major influence on when one schedules their defense, but people do talk about it, so (as a scientist!) I can't help but wonder if there's any truth behind the idea.

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    +1 for overthinking it. :) You'll do fine I'm sure, just don't schedule it for midnight or something.
    – badroit
    Apr 23, 2014 at 23:09
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    Do you really have that much freedom in scheduling? In my department, finding an hour when all the very busy committee members can be in the same room is always a struggle.
    – ff524
    Apr 23, 2014 at 23:18
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    @ff524 Me too. The challenge was getting 5 faculty members in a room at the same time, and it was scheduled for the single two-hour gap that could be found in the tangled nightmare that is faculty scheduling.
    – Fomite
    Apr 23, 2014 at 23:44
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    Maybe this depends on your academic system, but in most, unless your advisor is incompetent or your committee is insatiable, your chance of passing is 1. At very worst, 1-o(ε). The effect of the time of day is like o(ε³). Stop worrying! Apr 24, 2014 at 0:08
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    I'm just going to leave this here. Make sure you provide a small snack (cookies, cupcakes, traditional ethnic petit fours, etc.)!
    – Bill Barth
    Apr 24, 2014 at 1:15

4 Answers 4


First, I have never heard of any research backing up the idea that defenses will be more less successful based on the time of day the defense is held.

Second, the best time to defend is whenever your committee can actually make it. When I defended, my goal was to get get at least three of our four committee members in same physical room (one non-chair member could attend via video). Within a six-week window, I felt lucky to find any two hour-window to schedule the defense.

Finally, you are overthinking things. Pour your energy and concern into the content and remember that if your committee is encouraging you to defend, it's because they think you are ready. Surprises are unlikely.

Of course if you are in the enviable position of having to choose a time of day, I personally like defenses at the end of the work day so that you can head out with others — e.g., students, family members, maybe even committee members — for a celebratory post-defense drink or meal.

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    I'm not disputing that any of this is true, but only the first paragraph really gets at what I'm asking. It's a precondition of the question that the committee members' availability does not determine a time, so saying the best time is whenever they can make it kind of dodges the question, and also I'm asking out of curiosity so it doesn't help me to be told I'm overthinking things. (I know it's silly to use this criterion to determine a time. But if I weren't a PhD candidate at all, that paragraph wouldn't make much sense :-P)
    – David Z
    Apr 24, 2014 at 5:58
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    @DavidZ, people interested in the best time of day to schedule a thesis will almost universally be PhC's. They will almost universally be worried by the fact that their fate in others' hands and so are worrying about the the little things they can control. The last paragraph also gives you a concrete suggestion for when to schedule your thesis and a reason why. :)
    – mako
    Apr 24, 2014 at 6:08
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    For the sake of argument: my defense is long past and I'm still interested :-P
    – David Z
    Apr 15, 2015 at 16:23
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    @DavidZ, Fair enough!
    – mako
    Apr 15, 2015 at 16:24

Whatever time of day all your committee members can all get together. (Forgive the short answer but that's really it from my perspective)

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    There is nothing new in this answer that wasn't already in Benjamin's original answer above.
    – aeismail
    Sep 26, 2018 at 2:21
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    @aeismail, I didn't mean to offend. I actually upvoted his answer. It is good. I hope it keeps more votes. However I felt a short, to the point answer was appropriate too. I've seen answers overlap a lot on Academia.SE. I'll reread the answer guidance to be sure I'm on target. Thanks for keeping me straight. Sep 26, 2018 at 3:24
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    There can be overlap, but when the entirety of an answer is subsumed in another, it's considered poor form. (Also, a one-sentence answer is generally frowned upon, particularly on "soft" sites where the questions and answers tend to be more experience- and opinion-based by their nature.)
    – aeismail
    Sep 26, 2018 at 3:26
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    @aeismail, Thank you. I agree regarding one sentence answers but I respectfully feel a one-sentence answer is very appropriate here. I didn't consider the "poor-form" part and will work to avoid that in the future. Thanks for the lesson learned! Sep 26, 2018 at 3:33
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    @aeismail I think that this answer is good because it makes clear in one line what is the most important thing. The other answer is less strong in this sense. Sep 26, 2018 at 8:18

I had mine at 1 pm. It finished at 3:30, which gave me one and a half hours to make all the necessary corrections and then get to the pub.

In retrospect, 1 pm was a good time. I'm not a morning person by any stretch of the imagination. 1 pm allowed me to roll out of bed at 10 am, have a good full English breakfast and have an hour just to flick through the thesis and post https://xkcd.com/1403/ on social media channels. If you're a morning person that's always super alert at the time of 9 am, then try to schedule it as early as possible in the morning.

Really, you know what time of day you personally feel most alert and responsive. Given the flexible working nature of a lot of PhD students, you've probably settled into a working routine that works well for you by now. My recommendation would be to plan it around that.

  • Sorry I just noticed this - definitely good advice. It's not quite in the spirit in which I intended the question, i.e. taking all else to be equal (including what time of day the student is the best suited to work), is there a better time and what is it, but I wouldn't hesitate to endorse this to any student actually concerned with scheduling their defense. (Fun fact: that comic was posted the same day I defended.)
    – David Z
    Nov 19, 2018 at 9:08

This answer is the one I would accept. But, I know of one notable exception.

A friend in my PhD grad program choose his defense time for late morning (around 10 am) on a Tuesday. That way, his public defense would get done around 11 am and his closed door defense with only his committee would take less than a hour because his major advisor and several committee members always went to a local restaurant for their "Taco Tuesday" special around 11:45 am.

This worked for him, but my major advisor made me pick a different time when I tried to repeat the trick.

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