diff --git a/glossary.tex b/glossary.tex
index c9ab56b532aea21e6d055c264721dee5a1de25e3..3b66dcc09ff33d3ee82b5836e1ca6d5a4bb4a808 100644
--- a/glossary.tex
+++ b/glossary.tex
@@ -41,6 +41,12 @@
   nonumberlist,
 ]{lv}{Lv}{Spell Level}
 
+\newacronym[
+  description={is the universal way to measure time in \glsentrytext{fenestra}, where one \glsentrytext{cycle} equals three `years'},
+  name={Gnomish Machine Time (GMT)},
+  prefix={a\space},
+]{gmt}{GMT}{Gnomish Machine Time}
+
 \newacronym[
   description={are the smallest unit of currency},
   shortplural={cp},