# Why is Birthdate quantitative?

Shouldn’t it be qualitative? A Date of Birth is a single day. I don’t see the how much there is of something(taken from the lesson). It basically names the day a person was born.
I’m not sure whether I’m overthinking it

Yes I believe it’s better to consider it quantitative. I’ll give you onereason why and there would be an abundance of more examples if one took the time to look. And someone else could correct me if my reasoning is faulty.
For example when you use something like excel and insert dates on the backend the dates are just the number of days from a particular date (I believe 01/01/1900). So for example today’s date 8/27/2021 is equivalent to 44435. So for example if I wanted to find the number days between today and a week ago then I could do 8/27/2021 - 8/20/2021 or 44435 - 44428 which equals 7. Remember the criteria of quantitative variable. You have to be able to tell in which direction the differences go (like ordinal variables) also as an addition one is able to measure reliably how much greater one is than the other. That’s why you can use comparsion operators for example with dates.

@Rawrgunz55 thank you for taking the time to reply I finished the lesson earlier and your explanation is close to the mark. The link below is the eighth page of the lesson. The answer related to my question is there in significant detail.

https://app.dataquest.io/c/53/m/284/variables-in-statistics/8/common-examples-of-interval-scales

Birth dates are example of interval scales. Contrary to what I had assumed earlier, the date of birth signifies the number of days, months and years since the beginning of AD (Anno Domini system) on which a person is born.
The examples provided by you proves the conditions of direction and size.

1 Like

nice man . One thing in the statistics lessons is that there are going to be a lot of times when things don’t make sense the first time around. So the best thing anyone can do is just continue and finish the lesson. And if it still doesn’ t make sense what I would do in those situations was just review it the next day and it would click like a light bulb. I think it happened a lot during the conditional probability section for me lol.

1 Like

On point on that !! I haven’t got to that section yet.

You are right on the fact that many of the things light up as we progress in Stats. I’ve just started to realize that as well.

1 Like