diff --git a/README.md b/README.md
index 742c3693..b163c5f0 100644
--- a/README.md
+++ b/README.md
@@ -406,7 +406,7 @@ and B1900 epochs, respectively.
 
 TIRS (Terrestrial Intermediate Reference System) and its older equivalent PEF (Pseudo-Earth-Fixed) are not explicitly 
 referenced in SuperNOVAS. But they can be thought of as a special case of ITRS (International Terrestrial Reference 
-System) or TOD (True of Date) with DUT1 (= UT1-UTC), and the polar offsets (_dx_, _dy_) all set to zero.
+System) with DUT1 (= UT1-UTC), and the polar offsets (_dx_, _dy_) all set to zero.
 
 WGS84 has been superseded by ITRS for higher accuracy definitions of Earth-based locations. WGS84 matches ITRS to the 
 10m level globally, but it does not account for continental drifts and crustal motion. In (Super)NOVAS all Earth-fixed