todo.vim

function! HighlightDate(date)
	exec "syntax match TodoDateBeforeToday '" . a:date . "'"
	highlight link TodoDateBeforeToday TodoRed
endfunction

function! UpdateDateHighlights()
	let l:match = '\[\(\d\{2}\)\-\(\d\{2}\)\-\(\d\{4}\)\]'
	let l:yearToday = str2nr(strftime("%Y"))
	let l:line = 0
	while l:line < line('$')
		let l:date = matchlist(getline(l:line), l:match)
		if len(l:date) > 0
			let l:day = l:date[1]
			let l:month = l:date[2]
			let l:year = l:date[3]
			if l:year < l:yearToday
				call HighlightDate(l:date[0])
			endif
		endif
		let l:line = l:line + 1
	endwhile
endfunction

autocmd BufRead,InsertEnter,InsertLeave * call UpdateDateHighlights()