fixedcal/README.md

# FixedCal

Python package for international fixed calendar dates.

## What is that?

International fixed calendar is an alternative calendar system. It divides year into 13 even months by adding a month called Sol between June and July. Each month starts with Sunday and has exactly 28 days or 4 weeks. An additional _year day_ is added to the end of the year and it does not belong to any of the months and has no weekday. You can read more about IFC on [Wikipedia](https://en.wikipedia.org/wiki/International_Fixed_Calendar).

## Usage

### Date initialization

```python3
from fixedcal import FixedDate

# Date of today
fixed_date = FixedDate.today()

# From native datetime
from datetime import datetime
feburary_seventh = datetime(2022, 2, 7)
fixed_date = FixedDate(feburary_seventh)

# From day's ordinal in year
fixed_date = FixedDate(day_of_year=107, year=2022)
```

### Date's properties

```python3
from fixedcal import FixedDate
from datetime import datetime
fixed_date = FixedDate(datetime(2022, 8, 12))

fixed_date.datetime			# datetime(2022, 8, 12, 0, 0, 0)
fixed_date.day_of_year		# 224
fixed_date.day_of_month		# 28
fixed_date.month			# 8
fixed_date.year				# 2022
fixed_date.is_year_day		# False
fixed_date.week_of_month	# 4
fixed_date.weekday			# 7
fixed_date.week_of_year		# 32
fixed_date.year_quarter		# 3

```

### Date's operations

```python3
from fixedcal import FixedDate
from datetime import datetime, timedelta
fixed_date = FixedDate(datetime(2022, 12, 6))
jan_first = FixedDate(datetime(2023, 1, 1))

new_fixed = fixed_date + timedelta(3)	# FixedDate 3 days ahead
new_fixed = fixed_date - timedelta(2)	# FixedDate 2 days before
new_fixed = jan_first - fixed_date		# timedelta between dates

fixed_date == fixed_date				# True
fixed_date != jan_first					# True
jan_first < fixed_date					# False
```

### Year day

Year day is the day after the last of December and before the first of January. For that date, `FixedDate` gives the following property values.

* `day_of_year` = 365
* `day_of_month` = 1
* `month` = 14
* `year` is obviously the ending year
* `is_year_day` = True
* `week_of_month` = 1
* `weekday` = 1
* `week_of_year` = 53
* `year_quarter` = 4