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.
Is Your Thesis Defense Just a Formality, or Real Defense?
“Your thesis defense is in 3 weeks?” my best friend, Kat, asked me astonished when she heard that my defense date was finally approved.
“I am taking the day off from work, see you then,” she continued.
Kat drove from New York to Cambridge (over 200 miles each way) just to see my thesis defense, and she was not happy when my talk was over.
I didn’t disappoint my audience.
My talk was well-structured, and I explained all the research relevant to my thesis.
I was not in danger of “failing” either.
While my committee had high expectations from me, they asked very reasonable questions during my thesis defense.
However, I had one of those professors in my audience.
He always sat in the first row during seminars, and questioned every statement the speakers made.
During my thesis defense, however, he took it a step further.
He asked me a question that was only distantly related to my thesis, and I humbly told him I didn’t know the answer.
I was ready to continue, but he interrupted again with the same question.
I explained again that I hadn’t looked into that research question, and proceeded to move on.
But he didn’t give up.
He explained why that research question was so important and why it had to be addressed.
The room, filled over over 100 people, suddenly felt very hot.
I started to sweat under my freshly tailored dress shirt, and reached for my water bottle.
I glanced at my committee while I took a sip of water, hoping one of my committee members would interrupt this awkward dialogue.
But they just gave me blank stares.
Then, I sighed in relief.
“No one is out to get me, “ I realized.
“They just want to see how I perform under pressure.”
I turned back to the professor and smiled at him.
I respectfully told him that I agreed with his viewpoint, and that research question would be an excellent direction for future research.
The dialogue continued for about 10 more minutes, until the professor ran out of questions to “grill me” with.
I continued my thesis defense talk without any more interruptions from the audience.
After my talk was over, my committee had a brief closed door meeting.
When they called me back in, my thesis supervisor put his hand on my shoulder, and said “You did great.”
I knew he wasn’t referring to my thesis defense (which I passed), but to how I handled the questions from the other professor.
During my after-party, one of the senior staff members told me that she had never seen that professor be so tough on anyone else.
“Don’t take it personally,” she continued. “It’s just a rite of passage to the PhD world.”
Kat, gave me a big hug, and whispered in my ear that she had to restrain herself from giving the professor a black eye during his interrogation.
“Don’t worry,” I laughed. “This was his last chance to see how far he could push me.”
It was true.
That was my last talk at that department, but I gave many other research presentations during my postdoctoral fellowship and in the pharmaceutical industry.
At almost every talk there was one person who asked 80% of the questions, and was skeptical of everything I said.
But I always kept my calm, even when I presented to high level executives in industry.
I realized that no one expected me to know all the answers, but they did expect me to take ownership of my project and know how to find the answers.
In a strange way, the verbal beating during my thesis defense, was a gift that helped me to have more confidence in myself.
How would your life be different if you knew that no one was out to get you?
Would you be more bold about speaking up during meetings, or answering questions with confidence?
Most of the myths around the thesis defense stem from the fear that if you say the wrong thing, some will get you.
The worst that can happen is that they will disagree with you, and you will learn something new.
Most importantly, you will gain confidence to speak up in front of others, a skill that will serve you throughout your career.
5 Thesis Defense Myths That You Can Debunk Right Now
If you’re worried about your thesis defense, take a deep breath.
The reality is that for most students, the thesis defense is a formality.
By this point in your studies, you’re on track to graduate.
If you’ve been approved to defend your thesis, your success is almost 100% assured.
Still not sure? Here are five myths about the thesis defense, that might be causing you undue anxiety.
Myth 1: If you can’t answer every question, your thesis won’t be approved.
It’s always a good idea to prepare and practice for some questions before your thesis defense.
But don’t get stuck thinking you’ll be expected to know everything in order to pass your defense.
If you’ve conducted your research and written your thesis, you’re already, by definition, an expert in your field.
Being an expert doesn’t mean you have to have all the answers.
As you know, research is a never-ending journey, and there’s always more to learn no matter your level of expertise.
Your thesis committee knows this, too.
Your thesis defense is a chance for you to show that you’ve learned how to research independently.
If you’re asked a question you’re not sure about, it’s okay to admit you don’t know.
In fact, it’s good!
Don’t try to make up an answer…your committee will see through it.
Instead, explain how you would find out the answer
Remember, if you’ve made it to your thesis defense, the hard part is over.
You’ve already had your topic approved, done your research, and survived writing your thesis.
Myth 2: Your committee wants to catch you in a mistake
No one is out to get you.
In fact, your committee is on your side.
They want you to graduate.
You’re in control; it’s your job to lead your thesis defense.
This is your research, your education, and your future that’s on the line.
It’s normal for your thesis committee to challenge you, and hold you to a rigorous standard.
While you’re settling on a thesis topic and conducting your research, it can even be preferable to have a “tough” thesis committee.
But in the end, your committee wants you to finish your thesis and get your degree.
They wouldn’t have approved your thesis for defense if they didn’t think you were ready.
Your success reflects positively on them as instructors, and on their department.
Your committee doesn’t want to see you trapped in your program any more than you do.
It’s in your committee’s best interest that your thesis defense goes well.
Don’t worry that they’ll try to pick apart your mistakes or trap you with trick questions.
That’s not why they’re there!
In many cases, a thesis defense is a great way to bring the department together and showcase interestng research.
You can even view yourself as a role model for more junior students to give them “hope” that one day they can be in your shoes.
Your committee has already approved your thesis topic, and overseen your extensive research.
They know how much work you’ve devoted to your degree, and they’re not trying to trip you up at the last minute.
Try to relax, and have confidence that you probably know more than you realize.
Myth 3: You’ll have to start all over if your thesis defense doesn’t go well.
Take a moment to contemplate your fears.
What if your thesis defense really does bomb?
Or what if your committee wants you to make changes to your thesis before you can graduate?
In the unlikely event that this were to happen, you wouldn’t be back at square one.
Usually, in cases like these, the changes that are requested are extremely minor modifications that can be done fairly quickly.
Your thesis committee isn’t going to ask you to start researching all over again, or to drastically revise your thesis.
In a typical thesis defense, there aren’t many surprises.
Your committee will already be familiar with your work.
You’ve presumably already addressed any problems with your research.
If you’ve been given approval to defend your thesis, that means your committee is already confident in you and your research.
At this stage in your grad school career, there’s almost no chance your thesis defense won’t be approved.
But even if that were to happen, it would likely be a minor issue that you could quickly fix.
Even if the worst happens and you have to make revisions to your thesis, your graduation probably still won’t be delayed.
Myth 4: Your thesis committee members are the “real” experts in your field, not you.
A few weeks before I gave one of my first talks about my thesis, my thesis supervisor gave me a much-needed piece of advice.
I had been emailing him with questions all week.
What points did he think I should emphasize in my talk?
What should I be sure not to leave out?
My thesis supervisor was patient with my questions, but he finally had to remind me to rely on my own judgement.
“Your thesis is your own original research. You know the subject matter better than I do,” he said.
Of course, hhe was right.
He was familiar with my topic, but she hadn’t been there for the hours of lab work, I had.
I realized that I was already an expert, even if I didn’t have my PhD yet.
A thesis defense is a bit like an exam where the person being tested usually knows more than the people who are testing them.
When you present your thesis, you are the one with the first-hand experience and the knowledge.
Your thesis committee may have more overall experience, but they have their own projects and areas of expertise.
They’re relying on you to present them with your research.
By writing a thesis, you have become an authority.
In fact, you might be the most informed person at your institution on your particular topic.
So approach your thesis defense with confidence.
For almost everyone present, you’ll be teaching them something new.
Myth 5: If you’ve had a rocky path to your PhD, it will definitely show in your thesis defense.
The truth is, no two graduate degrees are alike.
Everyone takes a unique path to finishing their thesis and getting their degree, and it’s almost never easy.
If you struggled to make it to this stage, take comfort in knowing that most of your peers probably thought the same thing at some point.
But a bumpy road to finishing your thesis doesn’t mean your defense won’t go smoothly.
Even if your committee meetings were tough, or your research didn’t always go as planned, think of your thesis defense as a fresh start.
Your audience wasn’t with you every step of the way.
For the most part, they have no idea what your challenges were while you were working on your thesis.
Believe it or not, some of the best talks I’ve attended have been led by colleagues who struggled to finish their degrees.
If you’re confident during your thesis defense, it’ll shine through, and you’ll have your committee forgetting all about whatever hurdles there were along the way.
Are you apprehensive about your thesis defense?
Have questions about what to expect?
Share your story in the comments below, and I will respond to you directly.