How to Rotate X Tick Label in Canvas/CSS?

Elastic Stack Kibana
2

I was able to get close to what you are requesting. You may be able to use this as a starting point:

.flot-x-axis div {
    white-space: nowrap;
    transform:  rotate(-90deg);
    text-indent: -100%;
    transform-origin: top center;
    text-align: right !important;
    top: 280px !important;
}