Add UTC times

This may be easier for people outside the pacific time zone to read.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Change-Id: I715906fbec97dc439b0b35afc70e29edcebade97
diff --git a/index.md b/index.md
index c666fd7..c705fee 100644
--- a/index.md
+++ b/index.md
@@ -1,7 +1,7 @@
 # Git Contributors' Inclusion Summit
 
-Monday, September 14th 9am-12:30 pm PDT \
-Tuesday, September 15th 10am-2pm PDT
+Monday, September 14th 16:00-19:30 UTC (9am-12:30pm PDT) \
+Tuesday, September 15th 17:00-21:00 UTC (10am-2pm PDT)
 
 ## Purpose