define-command \
-docstring %{
    Insert the date, with the args passed as a string
    to date -d
} \
insert-date -params 1.. %{
    evaluate-commands -draft -save-regs '|' %{
        set-register | "date -d '%arg{@}' -f +%%Y-%%m-%%d"
        execute-keys '|<ret>'
    }
}