eday 1.0.6

A package for converting between dates and epoch days

The eday package provides functions for converting between dates and epoch days.

Epoch days represent the number of days since the Unix epoch (January 1, 1970, UTC).

Installation

You can install eday using pip:

pip install eday

Usage

The package provides three main functions:

1. from_date: Converts a date object or ISO format string to an equivalent number of days since the epoch.

2. to_date: Converts a number of days since the epoch to a datetime object in UTC.

3. now: Returns the current UTC time as a number of days since the epoch.

Example usage:

import eday

# Convert a date to epoch days
eday.from_date('1968-12-31')

# Convert epoch days to a datetime object
eday.to_date(20000)

# Get the current UTC time in epoch days
eday.now()

Shorthands

The package presents a converter aliased to package, that inherits from float, making the computations of date differences easier.

import eday

# Instantiate epoch days

eday('2024-10-04')
# OR
eday(20000)
# Use very large time days
eday(123812936129831283)

# Subtract or add dates:

eday('2024-10-04') - eday.now()
# OR timezone-specific:
eday('2018-01-13 04:15+09:00') - eday('2022-02-17 15:45-07:00')
# OR times:
eday('25:50') + eday('-0:05')
# (25:50 translates into 1 day 1:50 AM)

Negative times

Reading minus symbol from ISOString or TimeString is supported, like so:

# If "-" is prepended, then days since 1970-01-01 get mirrored around 1970-01-01
eday('-2024-10-04')
# -20000.0 <1915-03-31 00:00:00+00:00>

# If "N" is added, then number of days since 0001-01-01 are returned.
eday('N2024-10-04')

# If "-" and "N' is added, then days sine 0001-01-01 get mirrored around 0001-01-01
eday('-N2024-10-04')

# You can also use "-" and "N" with times
eday('N12:50') + eday('-N0:05')

Limitations

When using “N” prefix, negative days are mirrored, so B.C.E. seasons get inversed. This is something that in the future version we might fix, but it is not in the short term horizon.

Compatibility

The package is compatible with Python 2 (up to version 1.0.1) and Python 3 (from version 1.0.2). Under Python2, it relies on the dateutil module for Python 2 compatibility when parsing ISO format strings.

Using Epoch Days from Terminal

Linux users can also use the following zsh functions directly from the terminal to compute epoch days.

#!/bin/zsh
function eday { # eday now
 local n=$((($(date +%s%9N)/864)*1000))
 local day=${n:0:-14}; local hour=${n:(-14)}
 echo $day.${hour:0:${1-11}} # $1: precision
}

function d2e { # isodate -> eday
 local n=$((($(date -u --date="$1" +%s%9N)/864)*1000))
 local day=${n:0:-14}; local hour=${n:(-14)}
 echo $day.${hour} | sed 's/\.\?0*$//'
}

function e2d { # eday -> isodate
 local second=$(printf "%f" $(($1*86400)))
 echo $(date -u +"%Y-%m-%dT%H:%M:%S.%N%:z" -d "@$second")
}

To use these functions, save them in a file named eday.sh and source the file to make the functions available in your terminal session.

License

This package is licensed under the MIT License. See the LICENSE file for details.

Contributing

Contributions are welcome! Feel free to open an issue or submit a pull request on GitHub.

GitHub Repository

You can find the source code and contribute to the development of this package on GitHub: https://github.com/mindey/eday

More Information

For more information on epoch days and their applications, you can visit the following link:

• Simple Decimal Calendar