The interest calculation method is defined by the quotient DAYS/DAY
BASIS and, as a factor of the percentage calculation, results in the percentage calculation for the specific period, the interest
calculation variant.

**Linear interest calculation:**

- Amount = calculation base * percentage rate / 100 * DAYS / DAY BASIS

**Exponential interest calculation:**

- Amount = Calculation base * (q ** (DAYS / DAY BASIS) - 1)

- with the compounding factor q = 1 + percentage rate / 100 and

- ** as the power operator

The methods for calculating DAYS (number of days of corresponding calculation period) are:

- 1.

- The actual number of days (calendar days) between the two dates are calculated.

- 2.

- The number of days between the dates M1/D1/Y1 and M2/D2/Y2 is calculated on the basis of

- (Y2 - Y1) * 360 + (M2 - M1) * 30 + (D2 - D1).

- The month is calculated using 30 days and the 31st of each month is ignored for interest calculatiion purposes.

- Examples:

- 03/31 incl. to 04/02 incl. = 2 days

The 31st is not included.

- 12/01 incl. to 12/31 excl. = 30 days

The 31st is never included, so the addition of 'excl.' has no effect.

- 3.

- The number of days between the dates M1/D1/Y1 and M2/D2/Y2 is calculated on the basis of

- (Y2 - Y1) * 360 + (M2 - M1) * 30 + (D2 - D1).

- The month is calculated using 30 days and the 31st of each month is
considered to be the 30th, i.e. the 31st in D1 and D2 is reset to the 30th. This method is used on the Euromarkets.

- Examples:

- 03/31 incl. to 04/02 incl. = 3 days

The 03/31 is treated as the 30th and included because of the addition

'incl.'.

- 12/01 incl. to 12/31 excl. = 29 days

12/31 is treated as the 30th, but not included because of the addition

'excl.'.

The following are defined as **DAY BASIS**:

1. 360

- based on a year with 360 days.

2. 365

- based on a year with 365 days.

3. 366

- based on a year with 366 days.

4. 'actP'

- The suffix 'P' stands for 'period' to reflect that the actual number of
days in the period is used for the calculation. The days per year are
calculated by multiplying the number of days in a period by the number of periods per year.

Example:

Interest calculation method: act/actP

Six-monthly interest payments: Frequency 6 months

Calculation period: 01/01/1999 - 07/01/1999

The resulting DAYS / DAY BASIS quotient is:

181 / 362 = 181 / ( 181 * ( 12 / 6 ) ).

5. 'actY'

- The suffix 'Y' stands for 'year' to reflect that the actual number of
days in the calendar year is used for the calculation - 366 days in a
leap year, otherwise 365 days. If the calculation period extends across
two calendar years, and one of these years is a leap year, the interest is calculated in two steps.

Example:

Interest calcualtion method: act/actY

Calculation period: 12/01/1999 - 01/09/2000

The resulting DAYS / DAY BASIS quotient is:

39 / 365,2046825 = 31 / 365 + 8 / 366.

The combinations of DAYS / DAY BASIS used in practice and supported in Treasury Management are:

act/360, act/365, act/366, 360/360, 360E/360, act/actP, act/actY