create a TODO with the current date and start editing inside the comment

todate.vim

function! ToDate()
    exec ":normal! o"
    exec ":. ! echo '/** TODO: as of' $(date -I) ' */'"
    exec ':normal! k'
    exec ':normal! J'
    exec ':normal! A'
    exec ':normal! 2h'
    exec ':startinsert'
endfunction
map <leader>di :call ToDate()<CR>