Update README.md

README.md

@@ -70,7 +70,8 @@ the following two fields are needed.
 - `shows_seconds`: Whether seconds are shown
 
 For convenience, this dataset includes a few fields derived from this data about what is visible on the watch:
-- `hour_visible`: The hour visible on the watch, between 0 and 23, -1 means not visible, 0 is 12:00am
+- `hour_visible`: The hour visible on the watch, between 0 and 23, -1 means not visible, 0 is 12:00am.
+  If AM/PM cannot be determined the hour will be between 0 and 11
 - `minute_visible`: The minute the watch should be set to, between 0 and 59, -1 means not visible
 - `second_visible`: The second the watch should be set to, between -1 and 59, -1 means not visible
 - `text`: A text string of the time