Part -time job payday

I started to work in a company july 1.
I am partimer but i work everyday from morning to evening, as a full timer
The payday is day 15 so i was wondering if i will be payed for one month work or will i be payed one month and the 15 days i also worked.
As my work is per hours...
Because on day 15 i would have worked like one month and 15 days.
What is the system of japan.

Please explain ro me as i am pretty stupid understanding things like that.

why you do not ask the company you work for. I think they know best

It depends on the company, and the contract you signed.

Probably (as a reasonable guess) you will be paid for July in August. Next month you will be paid in September for August.

you have to know 〆日(closing date). generally speaking, payday is 2 or 3 weeks after the 〆日.
if payday is day 15, it is quite common that closing date is the end of month.
if so, if you worked from July 1, your work hours, from July 1 to the end of July, are calculated, and they pay the first salary on August 15.
they need some time to calculate your work hours and income tax.