It appears that you are currently using an outdated version of Charts.js. In Charts.js >2.0, axis labels should automatically expand to show the full date unless you specifically override the label function, as demonstrated here.
For a live demonstration, you can check out this demo: https://codepen.io/adelriosantiago/pen/wvooQRR?editors=1010
https://i.stack.imgur.com/FV5Sm.png
If you need to modify the date format, you can do so in options.scales
:
xAxes: [{
type: "time",
time: {
unit: 'hour',
unitStepSize: 0.5,
round: 'hour',
tooltipFormat: "h:mm:ss a",
displayFormats: {
hour: 'Y MMMM D, H:M:S A'
}
}
}]