1 files changed, 121 insertions, 0 deletions
diff --git a/datamaps/core/temporal.py b/datamaps/core/temporal.py
new file mode 100644
index 0000000..ddb7004
--- /dev/null
+++ b/datamaps/core/temporal.py
@@ -0,0 +1,121 @@
+import datetime
+
+
+class FinancialYear:
+    """An object representing a financial year.
+
+    Used by ``bcompiler`` internally when creating :py:class:`bcompiler.api.Master` objects.
+    Can be used to calculate start and ends dates and :py:class:`bcompiler.api.Quarter` objects.
+
+    If parameter ``year`` must be in the range 150 - 2100.
+
+    """
+
+    def __init__(self, year):
+        if isinstance(year, int) and (year in range(150, 2100)):
+            self.year = year
+        else:
+            raise ValueError("A year must be an integer between 1950 and 2100")
+        self._generate_quarters()
+        self._q1 = self.quarters[0]
+        self._q2 = self.quarters[1]
+        self._q3 = self.quarters[2]
+        self._q4 = self.quarters[3]
+
+        self.start_date = self.q1.start_date
+        self.end_date = self.q4.end_date
+
+    @property
+    def q1(self) -> datetime.date:
+        """Quarter 1 as a :py:class:`datetime.date` object
+        """
+        return self._q1
+
+    @property
+    def q2(self):
+        """Quarter 2 as a :py:class:`datetime.date` object
+        """
+        return self._q2
+
+    @property
+    def q3(self):
+        """Quarter 3 as a :py:class:`datetime.date` object
+        """
+        return self._q3
+
+    @property
+    def q4(self):
+        """Quarter 4 as a :py:class:`datetime.date` object
+        """
+        return self._q4
+
+    def __str__(self):
+        return f"FY{str(self.year)}/{str(self.year + 1)[2:]}"
+
+    def _generate_quarters(self):
+        self.quarters = [Quarter(x, self.year) for x in range(1, 5)]
+
+
+    def __repr__(self):
+        return f"FinancialYear({self.year})"
+
+
+class Quarter:
+    """An object representing a financial quarter. This is mainly required for building
+    a :py:class:`core.master.Master` object.
+
+    Args:
+        quarter (int): e.g.1, 2, 3 or 4
+        year (int): e.g. 2013
+    """
+    _start_months = {
+        1: (4, 'April'),
+        2: (7, 'July'),
+        3: (10, 'October'),
+        4: (1, 'January')
+    }
+
+    _end_months = {
+        1: (6, 'June', 30),
+        2: (9, 'September', 30),
+        3: (12, 'December', 31),
+        4: (3, 'March', 31),
+    }
+
+
+    def __init__(self, quarter: int, year: int) -> None:
+
+        if isinstance(quarter, int) and (quarter >= 1 and quarter <= 4):
+            self.quarter = quarter
+        else:
+            raise ValueError("A quarter must be either 1, 2, 3 or 4")
+
+        if isinstance(year, int) and (year in range(1950, 2100)):
+            self.year = year
+        else:
+            raise ValueError("Year must be between 1950 and 2100 - surely that will do?")
+
+        self.start_date = self._start_date(self.quarter, self.year)
+        self.end_date = self._end_date(self.quarter, self.year)
+
+    def __str__(self):
+        return f"Q{self.quarter} {str(self.year)[2:]}/{str(self.year + 1)[2:]}"
+
+    def _start_date(self, q, y):
+        if q == 4:
+            y = y + 1
+        return datetime.date(y, Quarter._start_months[q][0], 1)
+
+    def _end_date(self, q, y):
+        if q == 4:
+            y = y + 1
+        return datetime.date(y, Quarter._end_months[q][0], Quarter._end_months[q][2])
+
+    def __repr__(self):
+        return f"Quarter({self.quarter}, {self.year})"
+
+    @property
+    def fy(self):
+        """Return a :py:class:`core.temporal.FinancialYear` object.
+        """
+        return FinancialYear(self.year)