I was testing biz days and found a strange. Here follows a little code fragment:

from bizdays import *
cal = Calendar.load('files/cal/ANBIMA.cal') # path in my file system - should be changed
cal.offset('2016-11-03', -1)
cal.offset('2016-11-02', -1)

The first call to offset gives me the expected result:
Out[25]: datetime.date(2016, 11, 1)

The second one, however, does not:
Out[26]: datetime.date(2016, 10, 31)

I was expecting to get the exact same result (i.e. '2016-11-1').

The start and end dates should be passed in the constructor, instead of trying to guess.
The rule is use the first and last dates of the given calendar spec or use whatever is passed.

It would be nice to compare the date type and iso formatted strings.
It is awful convert from date to string and vice-versa to do computations and comparisons.

getdate has the following default call.

getdate(self, expr, year, month=None)

Instead of using year and month arguments it should use a now argument to specify where it is in time.

getdate(self, expr, now=datetime.today())

My code:

from bizdays import Calendar
holidays = ['2017-01-01','2017-04-2017','2017-05-2017','2017-09-07','2017-10-12','2017-11-11','2017-11-15','2017-12-25']
cal = Calendar(holidays=holidays, weekdays=['Sunday', 'Saturday'])
cal.isbizday('2017-11-01')

The output:
Traceback (most recent call last):
File "dias_uteis.py", line 10, in
cal = Calendar(holidays=holidays, weekdays=['Sunday', 'Saturday'])
File "/usr/local/lib/python2.7/dist-packages/bizdays.py", line 285, in init
self._holidays = [Date(d) for d in holidays]
File "/usr/local/lib/python2.7/dist-packages/bizdays.py", line 245, in init
d = datetime.strptime(d, format).date()
File "/usr/lib/python2.7/_strptime.py", line 328, in _strptime
data_string[found.end():])
ValueError: unconverted data remains: 17
*Test on cloud9 ide.

The empty calendar should be useful in situations like those where someone wants to compute business days considering only weekends (or any other day) as non-working days, so that a list of holidays couldn't be provided.
In situations like that start and end dates must be provided in order to define calendar's range.

Develop helper functions to load list of dates in any format stored in text files.

load_dates(file, formats=(format1, format2))

format_n_ should be specified with regular expressions.

2023-02-22 was included as holiday in B3.cal file by mistake.

For instance, there were deals for DI futures and the official calendar explicitly says it only had different negotiation time.

• work interchangeably with dates and string dates
• work interchangeably with sequences and single values
• recycle rule

In bizdays 1.0.2, in the getdate function, I'm unable to pass in '1st bizday before 2nd fri'

contractyear=2002
contractmonth=5
newltd=cal.getdate("1st bizday before 2nd fri",contractyear,contractmonth)

This shows:

  File ".../bizdays.py", line 888, in getdate
    dt = self._index.getdate(expr, year, month)
  File ".../bizdays.py", line 313, in getdate
    raise ValueError('Invalid reference day:', tok[4])
ValueError: ('Invalid reference day:', 'fri')

(Incidentally, the usage case for this is for futures market expiries - this one in particular is the 90 Day Bank Accepted Bills contract listed on the Australian Securities Exchange (formerly Sydney Futures Exchange).

Of course, I can do this is a nested fashion, as below, but it'd be nicer for the parser to handle this.

newltd=cal.offset(cal.getdate("2nd fri",contractyear,contractmonth),-1)

I create a Calendar using

>>> cal = Calendar(holidays, ['Sunday', 'Saturday'], name='Brazil')

and use getdate with

>>> cal.getdate('last wed', 2002, 5)

I should use short weekdays declaring Calendars

Setting iso=True returns ISO formatted date
iso=False returns datetime.date objects

The calendar doesn't have a name property, and it makes nonsense since I have to provide a name for the calendar.

Add an option to create dates with given timezone.

set_option('timezone', timezone.utc)

A project might set a specific option to bizdays.
But in another part, it needs to change this option.
This should be done locally with context managers.

from bizdays import set_option, Calendar, option

set_option("mode", "pandas")
cal = Calendar.load("B3")

with bizdays.option("mode", "datetime"):
    cal.bizdays(date1, date2)

Compare to:

• dateutil
• quantlib ?!?

A calendar register for applications which have many calendar.
Instead of creating many calendar instances a register should work as a repository for calendar that could be called by its name.

A offset method should be implemented.

cal.offset('2012-01-03', 6)
# returns the the date offset by 6, considering only the business days
# or
cal.offset('2012-01-03', -6)
# offset backward

it can be done with adjust_next and adjust_previous

Allow users set startdate and/or enddate even if holidays is provided.

Hi!
I got an unexpected error while trying to check a date using isbizday method.

>>> from bizdays import Calendar, load_holidays
>>> cal = Calendar.load("ANBIMA")
>>> cal.isbizday("2023-04-21")
False
>>> cal.isbizday('2023-04-20')
True

However, seeing the "ANBIMA.cal" file, we clearly visualize that 21 April's is a Holiday, but the bizday lib counts it as 20 April.

~ % python --version
Python 3.8.5

~ % uname -a
Darwin 21.3.0 Darwin Kernel Version 21.3.0: Wed Jan  5 21:37:58 PST 2022; root:xnu-8019.80.24~20/RELEASE_X86_64 x86_64

bizdays, current_days, adjust_next and adjust_previous should be vectorized.

enable the use of calendars from the project below

https://github.com/gerrymanoim/exchange_calendars

it is an implementation similar to what has been done to pandas_market_calendars.

I noticed when I installed bizdays it triggered a numpy downgrade:

 - numpy==2.0.0
 + numpy==1.26.4

The current pyproject.toml specifies numpy 1.x. It might be better to remove this entirely and then just pull in the numpy version corresponding to pandas 2.x:

numpy = ">=1.26.0"

How do you load a calendar from another package in the python version? In R I use bizdays all the time, its amazing. In that example, let's say I wanted to find the "last bizday" in a sequence and reference the Rmetrics/NYSE calendar:
bizdays::getdate("last bizday",as.Date(timeSequence(from = as.Date('2020-01-01'), to = as.Date('2022-12-31'), by = "1 month")),"Rmetrics/NYSE")

In the python version, if i loaded for example:
import pandas_market_calendars as mcal
cal = mcal.get_calendar('NYSE')
holidays = cal.holidays()
How can i pass these holidays to bizdays for getdate?

Thanks!!

Where to find the calendar spec?
The directory should be provided, or the path should be passed together with the calendar spec name, but the calendar's name wouldn't have the path.

cal = Calendar('/path/to/calendar/spec/Test')
cal.name
# Test

or specify the directory explicitly

cal = Calendar('Test', repository='/path/to/calendar/spec/')

or lastly a singleton to hold the settings.

bizdays.calendar_settings(repository='/path/to/calendar/spec/')

bizdays version 1.0.11

'bizdays' is returning wrong values.

Reproducible example (September 2022 has 21 business days with Anbima calendar):

bizdays("2022-09-01", "2022-09-30", "Brazil/ANBIMA")
20

bizdays("2022-09-01", "2022-10-01", "Brazil/ANBIMA")
20

However, that's correct:

length(bizseq(dmy("01/09/2022"), dmy("01/10/2022"), "Brazil/ANBIMA"))
21

bizdays doesn't handle correctly non-business days in edges.

The following call

bizdays("2013-01-01", "2014-01-01")

has two non-business days as arguments.
In this situation, the index counts one more bizday, which is incorrect.

The example below must return 0 since the arguments represent two consecutive dates non-business days.

bizdays("2013-06-22", "2013-06-23")

This specific case has to be handled separately but is similar to the first example.

getdate method in Vectorized object didn't remove adjust argument.

Currently the maximum supported Python version is 3.11; it would be great to be able to use this in 3.12 as well.