calculators

CWof(date)

the calendar week number of a date.

firstDayOfCW(year, cw, tzinfo=None)

first day of a numbered calendar week

daysOfWeek(year, cw, tzinfo=None)

yields 7 datetimes of the given calendar week

numberOfDaysInYear(dt)

calculates number of days of the given datetimes year

numberOfDaysInMonth(dt)

calculates number of days of the given datetimes month

daysOfMonth

yields all days as datetimes of the given month

hoursOfDay(year, month, day, tzinfo=None)

yields all hours of a day as datetimes

isSameDay(first, second)

detects if two dates are the same day. bool.

converter

dt2DT(dt)

Convert Python’s datetime to Zope’s DateTime. Acts timezone-aware.

DT2dt(DT)

Convert Zope’s DateTime to Pythons’s datetime. Acts timezone-neutral, outcome is on UTC.

dt2UTCString(dt)

build a ‘-’ separated string from the datetime timetuple as UTC.

dtFromUTCString(utcstr)

build datetime from timetuple UTC string.

dt2epochday(dt)

Number of days since epoch. timezone gets a problem here, we need to normalize all to GMT to make it recognize the same day even if it a different timezone: i.e. 2008-05-01T00:00:00+02:00 (CEST)

inspector

All functions are using the timezoneAdjuster (see below). therefore a context is passed

dtYear(dt, context=None):

year of datetime.

dtMonth(dt, context=None)

month of datetime.

dtDay(dt, context=None)

day of datetime.

dtHour(dt, context=None)

hour of datetime.

dtMinute(dt, context=None)

minute of datetime.

dtWeekday(dt, context=None)

Weekday of datetime.

pyDt

Detect wether dt is instance of datetime object.

recurring

Simple recurring features. for more sophisticated recurring feature refer to dateutils.rrule

recueDays(start, until, recuemode, offset)

Generates list of recue days.

timezone

Dealing with timezones is always pain. With these common features it get less pain. Using ZCA where registering a common TimezoneFactory using the computers system timezone. It is used by the timezoneAdjuster. If you register a more specific TimezoneFactory following its simple interface - its just a callable - , you can implement user configurated multi-timezone aware applications. This is all based on pytz, because pytz just works.

ServerTimezoneFactory(context)

The timezone of the server (current computer). You never need to use this directly.

timezoneAdjuster(context, dt)

New datetime with given timezone. Given datetime cant be naive!

tzawarenow()

timezone aware now datetime using utc timezone. if you need the current timezone adjust it.

2.0.0 (2026-10-31)

• Fix numberOfDaysInYear. It called isLeapYear, which only Zope’s DateTime provides, and failed for datetime objects. This also broke yearly recurring in recueDays. [rnix]

• Replace the deprecated datetime.utcnow in tzawarenow. Behaviour unchanged. [rnix]

• Declare DateTime as dependency. bda.calendar.base.converter and bda.calendar.base.recurring import it. [rnix]

• Drop the Python 2 remnants: implicit relative imports in bda.calendar.base.inspector, bda.calendar.base.recurring and bda.calendar.base.timezone. These modules were not importable on Python 3. [rnix]

• Add tests. Use pytest as test runner. [rnix]

• Sort the imports with ruff (one per line, from imports first, no sections) and format the code with ruff format (90 characters per line, single quotes). [rnix]

• Add Makefile (mxmake) with qa.ruff, qa.test and qa.coverage domains, pin the ruff configuration in pyproject.toml and add a GitHub Actions test workflow. [rnix]

• Move the changelog from README.rst to CHANGES.rst and the license to LICENSE.rst. [rnix]

• Refactor package layout to use pyproject.toml and implicit namespace packages. [rnix]

• Drop Python 2 support. Python >= 3.10 is required. [rnix]

1.2.5 (2022-12-05)

• Try again to release wheel with zest.releaser. [rnix]

1.2.4 (2022-12-05)

• Release wheel. [rnix]

1.2.3

• Remove superfluous import. [rnix, 2020-08-12]

1.2.2

• conditional ZCML for pyramid and zope. [rnix, 2011-11-16]