Bitcoin-Seconds (BXS) is a new framework for measuring time-weighted economic activity in Bitcoin-denominated systems. It defines a formal unit—one Bitcoin sustained for one second—to quantify how value accrues and decays through time. By combining on-chain data such as UTXO age, income, spending rate, and real inflation (sourced from Truflation), the BXS model produces a dimensionless index (BSₚ) representing economic vitality in "Bitcoin-time."

The paper introduces the BXS and SXS (Satoshi-Second) units, outlines their mathematical formulation, and presents an illustrative example using Satoshi Nakamoto’s estimated 968,452 BTC holdings. An open-source CLI tool accompanies the paper for empirical computation, enabling real-time analysis of Bitcoin-Seconds across wallets, entities, or networks.

This project aims to establish a consistent, verifiable, and physics-inspired foundation for temporal economics on a Bitcoin standard.