.datepicker-days .class-holiday {
    color: #f00;
    font-weight: bold;
}

.datepicker-days th.dow:first-child,
.datepicker-days td:first-child {
    color: #f00;
    font-weight: bold;
}
.datepicker-days th.dow:last-child,
.datepicker-days td:last-child {
    color: #00f;
    font-weight: bold;
}

/*
.datepicker-days td[data-day="2020/01/17"],
.datepicker-days td[data-day="2020/01/24"]
{
  color: #f00;
}
*/

.bootstrap-datetimepicker-widget table td.active,
.bootstrap-datetimepicker-widget table td.active:hover {
  background-color: #337ab7;
  color: #fff;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
}

.bootstrap-datetimepicker-widget table td span.active,
.bootstrap-datetimepicker-widget table td i.active {
  background-color: #337ab7;
  color: #fff;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
}