The IERS and adjustments to Coordinated Universal Time

The International Earth Rotation and Reference Systems Service (IERS) plays a critical role in determining the relationship between Coordinated Universal Time (UTC) and the variable Earth rotation (UT1). Earth orientation parameters (EOPs) that describe the relationship between UT1 and UTC can be determined very accurately with low latency. For real-time users, EOP predictions are provided. The IERS EOP products are available through a variety of methods. The IERS continues to evolve to meet the future needs of its users.