16b: A Compact 16-Bit Date Representation

Overview

16b is a lightweight and efficient library for encoding and decoding dates using only 16 bits (2 bytes). This allows compact storage and fast manipulation of dates, making it ideal for embedded systems, databases, and performance-critical applications.

Date Format (Bit Layout)

The 16-bit date is structured as follows:

YYYYYYYMMMMDDDDD

• 7 bits for the year (offset from 1970, supports 1970-2097)
• 4 bits for the month (1-12)
• 5 bits for the day (1-31)

This format ensures efficient encoding of common date values within a 2-byte integer.

Supported Languages

• C (c/date16.c)
• C++ (cpp/date16.cpp)
• Python (python/date16.py)

Installation

Clone the repository:

git clone https://github.com/iaseth/16b.git
cd 16b

C/C++

Compile with:

gcc -o 16b c/date16.c   # For C
g++ -o 16b cpp/date16.cpp # For C++

Run the executable:

./16b

Python

cd python
python3 date16.py

Usage

Encoding Example (C++)

int year = 2025, month = 3, day = 28;

// Encode the date
Date16 date (year, month, day);
cout << "Encoded: 0x" << hex << date.value() << " (" << dec << date.value() << ")" << endl;

// Decode back
cout << "Decoded: " << date.year() << "-" 
	 << date.month() << "-" 
	 << date.day() << endl;

Decoding Example (Python)

encoded_bytes = encode_date(2025, 3, 28)
print(f"Encoded (hex): {encoded_bytes.hex()}")  # Prints exactly 2 bytes

decoded_date = decode_date(encoded_bytes)
print(f"Decoded: {decoded_date}")  # (2025, 3, 28)

License

This project is licensed under the MIT License.

Contact

For questions, open an issue or reach out via GitHub Discussions.