[{ThisMonth}]
<<now format: 'YYYY/0MM'>>
I have the following in a tiddler, tagged $:/tags/ViewTemplate so it shows in all tiddlers. You may however transclude it in another tiddler.
\define set-tags() [[Journal]] [[$(currentTiddler)$]]
\define actions()
<$action-sendmessage
$message="tm-new-tiddler"
title=<<title>>
tags=<<set-tags>> />
\end
<$vars date=<<now "0MM-0DD">> title="$(date)$,Journal">
<$set name="tags" value=Journal>
<$button actions=<<actions>>>
<$list filter="[<tv-config-toolbar-icons>prefix[yes]]">
{{$:/core/images/new-journal-button}}
</$list>
Journal Entry
</$button>
</$set>
</$vars>
Regards
Tony