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

.bootstrap-datetimepicker-widget .picker-switch td span {
    height: 0;
    line-height: 0;
}