The day you receive your salary payment is "payday."
The amount you receive on that day is your "paycheck."
"Let's go to the restaurant tomorrow, tomorrow is payday."
"I used to get paid twice a month, now I get paid every two weeks. I know I'm getting the same annual salary, but somehow it feels like less because my paycheck is smaller."
"The payroll department automatically deducts $X from my paycheck and deposits it in my savings account. That's the only way I've ever been able to save money."