Method tz_up

src/modules/clock.cpp:490–495

}
void waybar::modules::Clock::cldShift_reset() { cldCurrShift_ = (months)0; }
void waybar::modules::Clock::tz_up() {
  const auto tzSize{tzList_.size()};
  if (tzSize == 1) return;
  size_t newIdx{tzCurrIdx_ + 1lu};
  tzCurrIdx_ = (newIdx == tzSize) ? 0 : newIdx;
}
void waybar::modules::Clock::tz_down() {
  const auto tzSize{tzList_.size()};
  if (tzSize == 1) return;