diff --git a/core/wiki/macros/timeline.tid b/core/wiki/macros/timeline.tid
index 60481ba7a..62f8782cf 100644
--- a/core/wiki/macros/timeline.tid
+++ b/core/wiki/macros/timeline.tid
@@ -1,9 +1,9 @@
 title: $:/core/macros/timeline
 tags: $:/tags/Macro
 
-\define timeline(limit:"100",format:"DDth MMM YYYY")
+\define timeline(limit:"100",format:"DDth MMM YYYY",subfilter:"")
 <div class="tc-timeline">
-<$list filter="[!is[system]has[modified]!sort[modified]limit[$limit$]eachday[modified]]">
+<$list filter="[!is[system]$subfilter$has[modified]!sort[modified]limit[$limit$]eachday[modified]]">
 <div class="tc-menu-list-item">
 <$view field="modified" format="date" template="$format$"/>
 <$list filter="[sameday{!!modified}!is[system]!sort[modified]]">
diff --git a/editions/tw5.com/tiddlers/macros/TimelineMacro.tid b/editions/tw5.com/tiddlers/macros/TimelineMacro.tid
index 0d2866257..74a00eec9 100644
--- a/editions/tw5.com/tiddlers/macros/TimelineMacro.tid
+++ b/editions/tw5.com/tiddlers/macros/TimelineMacro.tid
@@ -1,6 +1,6 @@
 title: TimelineMacro
 tags: Macros
-modified: 20140905084423561
+modified: 20140913100126081
 caption: timeline
 
 The timeline macro produces a list of tiddlers in reverse chronological order of modification date that is grouped by the date of the day of modification.
@@ -10,6 +10,19 @@ The timeline macro produces a list of tiddlers in reverse chronological order of
 |!Position |!Name |!Description |!Default |
 |1st |limit |The maximum number of tiddlers to list |100 |
 |2nd |format |A DateFormat string for formatting the date |DDth MMM YYYY |
+|3rd |subfilter |A subfilter to include in the timeline filter (see below)  | |
+
+The subfilter and limit parameters are spliced into the filter string like this:
+
+```
+[!is[system]$subfilter$has[modified]!sort[modified]limit[$limit$]eachday[modified]]
+```
+
+To restrict the timeline to a particular tag, the subfilter can be set to something like `tag[mytag]`:
+
+```
+<<timeline limit:10 subfilter:"tag[mytag]">>
+```
 
 ! Examples