Interpreting IF formula

SH_94

Dear community,

I have one complex formula as below and would like to ask what this formula plan to do:

Formula One

IIF((REGEX_Match([NUMBER], "(\d{12})")=-1
AND TONUMBER(Substring([NUMBER],2,2))<13
AND TONUMBER(Substring([NUMBER],4,2))<32)=-1,1,0)

Formula Two 

IIF((([DATETIME1] > "2021-05-04 23:59:59" AND [DATETIME1] < "2021-10-01 00:00:00"))=-1,1,0)

Could someone explain what is the function of this formula as i plan to edit the formula after understanding it.

Many thanks for the help

Qiu

@SH_94 
Just want to add to comment of @apathetichell .
Your "NUMBER" column is a 12 digit nu
IIF is a conditional statement defined as below.

IIF
IIF(bool, x, y): Returns x if bool is true, else returns y.

In your Formula One

Bool equals "(REGEX_Match([NUMBER], "(\d{12})")=-1 AND TONUMBER(Substring([NUMBER],2,2))<13 AND TONUMBER(Substring([NUMBER],4,2))<32) =-1"

X equals 1

Y equals 0.

So intention here is when all 3 conditions are True, it return 1, else 0.

But there is a catch here. according to the help of alteryx, the true is not always "-1".

Therefore I would modify your Formula One as below and same applies to Formula Two to be safe. 
In your case, there are identical though.

IIF((REGEX_Match([NUMBER], "(\d{12})")
AND TONUMBER(Substring([NUMBER],2,2))<13
AND TONUMBER(Substring([NUMBER],4,2))<32),1,0)

0404-SH_94 .yxmd