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README.md

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+# TimeHash
+
+TimeHash is a library for encoding and decoding timestamps into variable-precision time intervals. It creates a fuzzy, hierarchical representation of time, making it ideal for Big Data analysis, spatial-temporal computations, and efficient time-series indexing.
+
+By encoding Unix epoch seconds into a compact string using a custom alphabet (`01abcdef`), TimeHash allows you to quickly determine temporal proximity, find neighboring time windows, and adjust precision on the fly without complex datetime arithmetic.
+
+## Time Range & Precision
+TimeHash covers a 128-year interval from **January 1, 1970** to **January 1, 2098**. Each character added to the hash reduces the time interval ambiguity by a factor of 8.
+
+| Length | Approximate Precision (±) |
+|:------:|:--------------------------|
+| 0      | 64 years                  |
+| 1      | 8 years                   |
+| 2      | 1 year                    |
+| 3      | 45.6 days                 |
+| 4      | 5.7 days                  |
+| 5      | 17.1 hours                |
+| 6      | 2.14 hours                |
+| 7      | 16.05 minutes             |
+| 8      | 2.01 minutes              |
+| 9      | 15.04 seconds             |
+| 10     | 1.88 seconds              |
+
+## Supported Languages
+TimeHash has been implemented in multiple languages:
+- Python (`timehash` package)
+- C (`c-impl/`)
+- C++ (`time_hash.h`)
+- C# / .NET (`TimeHash.cs`)
+- Go (`timehash.go`)
+- Java (`TimeHash.java`)
+- Perl (referenced in project history)
+
+## Installation (Python)
+Install the Python package via `pip`:
+```bash
+pip install timehash
+```
+Or install from source:
+```bash
+git clone https://github.com/abeusher/timehash.git
+cd timehash
+pip install .
+```
+
+## Usage (Python)
+```python
+from timehash import encode, decode, decode_exactly, before, after, neighbors, expand
+from datetime import datetime
+import time
+
+# Encode the current time with 10 characters of precision
+current_time = time.time()
+th = encode(current_time, precision=10)
+print(f"TimeHash: {th}")
+
+# Decode back to epoch seconds
+epoch = decode(th)
+print(f"Decoded epoch: {epoch}")
+
+# Decode with margin of error
+center, error = decode_exactly(th)
+print(f"Center: {center} ± {error} seconds")
+
+# Get neighboring time windows at the same precision
+prev_th = before(th)
+next_th = after(th)
+print(f"Previous: {prev_th} | Next: {next_th}")
+
+# Get all three (before, current, after)
+window = expand(th)
+print(f"Time window: {window}")
+
+# Encode directly from a datetime object
+dt = datetime(2023, 10, 25, 14, 30, 0)
+dt_th = encode_from_datetime(dt, precision=8)
+print(f"Datetime TimeHash: {dt_th}")
+```
+
+## API Overview
+| Function | Description |
+|----------|-------------|
+| `encode(epoch_time, precision)` | Encodes a floating-point Unix timestamp into a TimeHash string. |
+| `decode(timehash)` | Decodes a TimeHash string back to a floating-point Unix timestamp. |
+| `decode_exactly(timehash)` | Returns `(center, error)` representing the window midpoint and half-margin in seconds. |
+| `before(timehash)` / `after(timehash)` | Returns the adjacent TimeHash strings at the same precision level. |
+| `neighbors(timehash)` | Returns `[before, after]` list. |
+| `expand(timehash)` | Returns `[before, current, after]` list. |
+| `encode_from_datetime(datetime_obj, precision)` | Converts a Python `datetime` object directly to a TimeHash. |
+
+## License
+TimeHash is released under the **BSD 3-Clause License**. See the source files for full copyright and disclaimer information.
+
+## Contributors & History
+Created by **Abe Usher** in 2010. TimeHash has been improved through feedback and contributions from Dan Noble, Danny Holloway, Michele Bueno, David Sherman, Kevin Dwyer, Michele Casey (Java), and Altaf Bahora (Perl). A full history of changes is available in [CHANGES.md](CHANGES.md).