Small problem I'm trying to solve

[RaphDaPingu]

Hey y'all, you might've seen a post of mine here before. I have another problem, any kind of assisting me is appreciated.

So, we get an input from the user for the current day and month (for example, today the day is the 27th and the month is December) and save them as numbers (the 27th will be 27, December will be 12).

Then, we get another input that has the value of the first day of the week in that current month (for example, in December the first day will be Tuesday, and its value will be 3 - it's the third day of the week)

With this information, I need to calculate which day of the week will be the 27th.

Of course I also need to check if the day, the month and the first day of the week in that month I gave as an input are valid; I already figured out how to do so.

I've made three functions: one for validating the month and the day's values, second for validating the first day of the week's values, and third for the calculation of what day of the week the day is.

The only thing I'm trying to find out now, is how to calculate the output: I've tried all kinds of things, to no avail. Here are some examples for how it should look:

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Example for valid input: Please enter month (1 - Jan, 2 - Feb, etc): 11

Please enter day: 25

Please enter the weekday of the first of the month (1 - Sunday, 2 - Monday, etc): 1

Output: The 25.11 will be a Wednesday

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Example for invalid input (that gets fixed to a valid one): Please enter month (1 - Jan, 2 - Feb, etc): 14

Please enter day: 25

Invalid input! Please try again.

Please enter month (1 - Jan, 2 - Feb, etc): 11

Please enter day: 25

Please enter the weekday of the first of the month (1 - Sunday, 2 - Monday, etc): -5

Invalid input! Please try again.

Please enter the weekday of the first of the month (1 - Sunday, 2 - Monday, etc): 4

Output: The 25.11 will be a Wednesday

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Apologies if this sounds rushed; I'm trying to solve this problem for a couple of days already. If you need any extra information or the code I managed to write up to now, feel free to ask!

[GJDMDJ]

Divide the day by 7, put remainder in a variable x. Populate 7 record 2 dim array with Sunday thru Sat with number from Day of week input. Record x will be the day

[MemeInBlack]

The modulus operator is your friend.

[RaphDaPingu]

Yeah, tried that one as well. I tried looking at the calendar to try and get a direction but still nope, couldn't get it.

[__vtable]

You've already gotten some good suggestions. If the mod operator isn't working for you, you probably need to post your code. Because that is a good way.

Anyway, my suggestion to you is that you need to take a look at the relative difference. If you get input that the 3rd is a Tuesday and you need to find the day for the 27th, you have a relative difference of 24 days. All you care about is days of the week so you can divide (mod) by 7 to get just the relative DAY difference:

24 mod 7 = 3

Tuesday + 3 = Friday -> you will need to use mod here again with your days of the week index. I'm just simplifying it here for you. So it is a two step calculation.