Actual/365

Bases: Convention

Implements the Actual/365 Fixed day count convention.

Counts the actual number of days between two dates, excluding the end date, and divides by 365 to compute the year fraction. Suitable for compound interest calculations and XIRR when use_xirr_method is True.

Parameters:

Name	Type	Description	Default
use_post_dates	bool	If True, uses cash flow post dates for day counts; if False, uses value dates. Defaults to True.	True
include_non_financing_flows	bool	If True, includes non-financing cash flows (e.g., fees) in factor computations; if False, excludes them. Defaults to False.	False
use_xirr_method	bool	If True, uses the XIRR method, setting day count origin to DRAWDOWN; if False, uses NEIGHBOUR. Defaults to False.	False

Examples:

>>> dc = Actual365()
>>> factor = dc.compute_factor(
...     pd.Timestamp('2020-01-28', tz='UTC'),
...     pd.Timestamp('2020-02-28', tz='UTC')
... )
>>> print(factor)
f = 31/365 = 0.08493151

Source code in curo/daycount/actual_365.py

class Actual365(Convention):
    """
    Implements the Actual/365 Fixed day count convention.

    Counts the actual number of days between two dates, excluding the end date, and
    divides by 365 to compute the year fraction. Suitable for compound interest
    calculations and XIRR when `use_xirr_method` is True.

    Args:
        use_post_dates: If True, uses cash flow post dates for day counts; if False, uses
            value dates. Defaults to True.
        include_non_financing_flows: If True, includes non-financing cash flows (e.g., fees)
            in factor computations; if False, excludes them. Defaults to False.
        use_xirr_method: If True, uses the XIRR method, setting day count origin to
            DRAWDOWN; if False, uses NEIGHBOUR. Defaults to False.

    Examples:
        >>> dc = Actual365()
        >>> factor = dc.compute_factor(
        ...     pd.Timestamp('2020-01-28', tz='UTC'),
        ...     pd.Timestamp('2020-02-28', tz='UTC')
        ... )
        >>> print(factor)
        f = 31/365 = 0.08493151
    """
    def __init__(
        self,
        use_post_dates: bool = True,
        include_non_financing_flows: bool = False,
        use_xirr_method: bool = False
    ):
        super().__init__(
            use_post_dates=use_post_dates,
            include_non_financing_flows=include_non_financing_flows,
            use_xirr_method=use_xirr_method
        )

    def compute_factor(self, start: pd.Timestamp, end: pd.Timestamp) -> DayCountFactor:
        """
        Computes the year fraction between two dates using Actual/365 Fixed.

        Args:
            start: The earlier date (pd.Timestamp).
            end: The later date (pd.Timestamp).

        Returns:
            DayCountFactor: The year fraction (days / 365) with operand log.

        Raises:
            ValueError: If `end` is before `start`.

        Examples:
            >>> dc = Actual365()
            >>> factor = dc.compute_factor(
            ...     pd.Timestamp('2020-01-28', tz='UTC'),
            ...     pd.Timestamp('2020-02-28', tz='UTC')
            ... )
            >>> factor.primary_period_fraction
            0.08493150684931507
            >>> factor.discount_factor_log
            ['31/365']
        """
        if end < start:
            raise ValueError("end must be after start")
        days = (end - start).days if end > start else 0  # Exclude end date, 0 for same day
        factor = days / 365
        return DayCountFactor(
            primary_period_fraction=factor,
            discount_factor_log=[f"{days}/365"]
        )

compute_factor(start, end)

Computes the year fraction between two dates using Actual/365 Fixed.

Parameters:

Name	Type	Description	Default
start	Timestamp	The earlier date (pd.Timestamp).	required
end	Timestamp	The later date (pd.Timestamp).	required

Returns:

Name	Type	Description
DayCountFactor	DayCountFactor	The year fraction (days / 365) with operand log.

Raises:

Type	Description
ValueError	If end is before start.

Examples:

>>> dc = Actual365()
>>> factor = dc.compute_factor(
...     pd.Timestamp('2020-01-28', tz='UTC'),
...     pd.Timestamp('2020-02-28', tz='UTC')
... )
>>> factor.primary_period_fraction
0.08493150684931507
>>> factor.discount_factor_log
['31/365']

Source code in curo/daycount/actual_365.py

def compute_factor(self, start: pd.Timestamp, end: pd.Timestamp) -> DayCountFactor:
    """
    Computes the year fraction between two dates using Actual/365 Fixed.

    Args:
        start: The earlier date (pd.Timestamp).
        end: The later date (pd.Timestamp).

    Returns:
        DayCountFactor: The year fraction (days / 365) with operand log.

    Raises:
        ValueError: If `end` is before `start`.

    Examples:
        >>> dc = Actual365()
        >>> factor = dc.compute_factor(
        ...     pd.Timestamp('2020-01-28', tz='UTC'),
        ...     pd.Timestamp('2020-02-28', tz='UTC')
        ... )
        >>> factor.primary_period_fraction
        0.08493150684931507
        >>> factor.discount_factor_log
        ['31/365']
    """
    if end < start:
        raise ValueError("end must be after start")
    days = (end - start).days if end > start else 0  # Exclude end date, 0 for same day
    factor = days / 365
    return DayCountFactor(
        primary_period_fraction=factor,
        discount_factor_log=[f"{days}/365"]
    )