diff --git a/runtime/doc/undo.txt b/runtime/doc/undo.txt
index 1ed2ecd..d1433d5 100644
--- a/runtime/doc/undo.txt
+++ b/runtime/doc/undo.txt
@@ -145,6 +145,16 @@
 :earlier {N}s		Go to older text state about {N} seconds before.
 :earlier {N}m		Go to older text state about {N} minutes before.
 :earlier {N}h		Go to older text state about {N} hours before.
+:earlier {N}d		Go to older text state about {N} days before.
+
+:earlier {N}f		Go to older text state {N} file writes before.
+			When changes were made since the laste write
+			":earlier 1f" will revert the text to the state when
+			it was written.  Otherwise it will go to the write
+			before that.
+			When at the state of the first file write, or when
+			the file was not written, ":earlier 1f" will go to
+			before the first change.
 
 							*g+*
 g+			Go to newer text state.  With a count repeat that many
@@ -154,6 +164,11 @@
 :later {N}s		Go to newer text state about {N} seconds later.
 :later {N}m		Go to newer text state about {N} minutes later.
 :later {N}h		Go to newer text state about {N} hours later.
+:later {N}d		Go to newer text state about {N} days later.
+
+:later {N}f		Go to newer text state {N} file writes later.
+			When at the state of the last file write, ":later 1f"
+			will go to the newest text state.
 
 
 Note that text states will become unreachable when undo information is cleared