**        year-month-day form, it may be truncated, the "T" may be
**        replaced by a space, and it may also name a timezone offset
**        from UTC as "-HH:MM" (westward) or "+HH:MM" (eastward).
**        Either no timezone suffix or "Z" means UTC.
**
** Options valid for all subcommands:
**
**    -R|--repository REPO       Run commands on repository FILE
*/
void branch_cmd(void){
  int n;
  const char *zCmd = "list";
  db_find_and_open_repository(0, 0);
  if( g.argc>=3 ) zCmd = g.argv[2];
  n = strlen(zCmd);