What is the difference between biweekly and semimonthly payroll?

Definition of Biweekly Payroll
Biweekly payroll refers to paydays that occur 26 times per year (52 weeks in a year divided by 2 weeks = 26 times per year). With 26 paydays in the year and 12 months in a year, some months will have 3 biweekly paydays since 26 paydays divided by 12 months = 2.16667 paydays per month.

Definition of Semimonthly Payroll
Semimonthly payroll refers to paydays that occur 24 times per year (12 months in a year multiplied by 2 paydays per month = 24 paydays). With 52 weeks in a year and 12 months in a year, each semimonthly pay period will have on average 2.16667 weeks per semimonthly payday.

Example of Biweekly Payroll
Let's assume that a company pays its employees biweekly on every other Friday. If a new employee agrees to an annual salary of $52,000 the employee will be earning $2,000 ($52,000 divided by 26 paydays) during each biweekly pay period. The employee's pay records will indicate a gross salary of $2,000 each biweekly payday.

Example of Semimonthly Payroll
Now let's assume that another company pays its employees semimonthly on the 15th day and the last day of every month. If it hires a new employee at an annual salary of $52,000 the employee will be earning $2,166.67 ($52,000 divided by 24 paydays) during each semimonthly pay period. The employee's pay records will indicate a gross salary of $2,166.67 each semimonthly payday.