Date Conventions

General Notes

• Only include one of the endpoint dates
• Time must always be in years

Exact Simple Interest

• “actual/actual” method
• Include leap year days
• Include actual month days

Ordinary Simple Interest

• “30/360” method
• All months have 30 days and all years have 360 days
• Rules for changing dates
  • If any endpoint is 31, change it to 30
  • If any endpoint is 02/28 or 02/29, change it to 30
• The number of days $N$ is:

Banker’s Interest

• “actual/360” method
• Use the actual number of days but all years have 360 days