Анимация часов с участием CSS и Javascript

<div id="clock" class="progress-clock">
  <button class="progress-clock__time-date" data-group="d" type="button">
  <small data-unit="w">Sunday</small><br>
  <span data-unit="mo">January</span>
  <span data-unit="d">1</span>
  </button>
  <button class="progress-clock__time-digit" data-unit="h" data-group="h" type="button">12</button><span class="progress-clock__time-colon">:</span><button class="progress-clock__time-digit" data-unit="m" data-group="m" type="button">00</button><span class="progress-clock__time-colon">:</span><button class="progress-clock__time-digit" data-unit="s" data-group="s" type="button">00</button>
  <span class="progress-clock__time-ampm" data-unit="ap">AM</span>
  <svg class="progress-clock__rings" width="256" height="256" viewBox="0 0 256 256">
  <defs>
  <linearGradient id="pc-red" x1="1" y1="0.5" x2="0" y2="0.5">
  <stop offset="0%" stop-color="hsl(343,90%,55%)" />
  <stop offset="100%" stop-color="hsl(323,90%,55%)" />
  </linearGradient>
  <linearGradient id="pc-yellow" x1="1" y1="0.5" x2="0" y2="0.5">
  <stop offset="0%" stop-color="hsl(43,90%,55%)" />
  <stop offset="100%" stop-color="hsl(23,90%,55%)" />
  </linearGradient>
  <linearGradient id="pc-blue" x1="1" y1="0.5" x2="0" y2="0.5">
  <stop offset="0%" stop-color="hsl(223,90%,55%)" />
  <stop offset="100%" stop-color="hsl(203,90%,55%)" />
  </linearGradient>
  <linearGradient id="pc-purple" x1="1" y1="0.5" x2="0" y2="0.5">
  <stop offset="0%" stop-color="hsl(283,90%,55%)" />
  <stop offset="100%" stop-color="hsl(263,90%,55%)" />
  </linearGradient>
  </defs>
  <!-- Days of Month -->
  <g data-units="d">
  <circle class="progress-clock__ring" cx="128" cy="128" r="74" fill="none" opacity="0.1" stroke="url(#pc-red)" stroke-width="12" />
  <circle class="progress-clock__ring-fill" data-ring="mo" cx="128" cy="128" r="74" fill="none" stroke="url(#pc-red)" stroke-width="12" stroke-dasharray="465 465" stroke-dashoffset="465" stroke-linecap="round" transform="rotate(-90,128,128)" />
  </g>
  <!-- Hours of Day -->
  <g data-units="h">
  <circle class="progress-clock__ring" cx="128" cy="128" r="90" fill="none" opacity="0.1" stroke="url(#pc-yellow)" stroke-width="12" />
  <circle class="progress-clock__ring-fill" data-ring="d" cx="128" cy="128" r="90" fill="none" stroke="url(#pc-yellow)" stroke-width="12" stroke-dasharray="565.5 565.5" stroke-dashoffset="565.5" stroke-linecap="round" transform="rotate(-90,128,128)" />
  </g>
  <!-- Minutes of Hour -->
  <g data-units="m">
  <circle class="progress-clock__ring" cx="128" cy="128" r="106" fill="none" opacity="0.1" stroke="url(#pc-blue)" stroke-width="12" />
  <circle class="progress-clock__ring-fill" data-ring="h" cx="128" cy="128" r="106" fill="none" stroke="url(#pc-blue)" stroke-width="12" stroke-dasharray="666 666" stroke-dashoffset="666" stroke-linecap="round" transform="rotate(-90,128,128)" />
  </g>
  <!-- Seconds of Minute -->
  <g data-units="s">
  <circle class="progress-clock__ring" cx="128" cy="128" r="122" fill="none" opacity="0.1" stroke="url(#pc-purple)" stroke-width="12" />
  <circle class="progress-clock__ring-fill" data-ring="m" cx="128" cy="128" r="122" fill="none" stroke="url(#pc-purple)" stroke-width="12" stroke-dasharray="766.5 766.5" stroke-dashoffset="766.5" stroke-linecap="round" transform="rotate(-90,128,128)" />
  </g>
  </svg>
</div>

.progress-clock {
  display: grid;
  justify-content: center;
  align-content: center;
  position: relative;
  text-align: center;
  width: 16em;
  height: 16em;
}
.progress-clock__time-date,
.progress-clock__time-digit,
.progress-clock__time-colon,
.progress-clock__time-ampm {
  transition: color 0.2s linear;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
}
.progress-clock__time-date,
.progress-clock__time-digit {
  background: transparent;
}
.progress-clock__time-date,
.progress-clock__time-ampm {
  grid-column: 1 / 6;
}
.progress-clock__time-date {
  font-size: 0.75em;
  line-height: 1.33;
}
.progress-clock__time-digit,
.progress-clock__time-colon {
  font-size: 2em;
  font-weight: 400;
  grid-row: 2;
}
.progress-clock__time-colon {
  line-height: 1.275;
}
.progress-clock__time-ampm {
  cursor: default;
  grid-row: 3;
}
.progress-clock__rings {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}
.progress-clock__ring {
  opacity: 0.1;
}
.progress-clock__ring-fill {
  transition:
  opacity 0s 0.3s linear,
  stroke-dashoffset 0.3s ease-in-out;
}
.progress-clock__ring-fill--360 {
  opacity: 0;
  stroke-dashoffset: 0;
  transition-duration: 0.3s;
}
[data-group]:focus {
  outline: transparent;
}
[data-units] {
  transition: opacity 0.2s linear;
}
[data-group="d"]:focus,
[data-group="d"]:hover {
  color: hsl(333,90%,55%);
}
[data-group="h"]:focus,
[data-group="h"]:hover {
  color: hsl(33,90%,55%);
}
[data-group="m"]:focus,
[data-group="m"]:hover {
  color: hsl(213,90%,55%);
}
[data-group="s"]:focus,
[data-group="s"]:hover {
  color: hsl(273,90%,55%);
}
[data-group]:focus ~ .progress-clock__rings [data-units],
[data-group]:hover ~ .progress-clock__rings [data-units] {
  opacity: 0.2;
}
[data-group="d"]:focus ~ .progress-clock__rings [data-units="d"],
[data-group="d"]:hover ~ .progress-clock__rings [data-units="d"],
[data-group="h"]:focus ~ .progress-clock__rings [data-units="h"],
[data-group="h"]:hover ~ .progress-clock__rings [data-units="h"],
[data-group="m"]:focus ~ .progress-clock__rings [data-units="m"],
[data-group="m"]:hover ~ .progress-clock__rings [data-units="m"],
[data-group="s"]:focus ~ .progress-clock__rings [data-units="s"],
[data-group="s"]:hover ~ .progress-clock__rings [data-units="s"] {
  opacity: 1;
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
  :root {
  --bg: hsl(var(--hue),10%,10%);
  --fg: hsl(var(--hue),10%,90%);
  }
  .progress-clock__ring {
  opacity: 0.2;
  }
}

window.addEventListener("DOMContentLoaded",() => {
  const clock = new ProgressClock("#clock");
});

class ProgressClock {
  constructor(qs) {
  this.el = document.querySelector(qs);
  this.time = 0;
  this.updateTimeout = null;
  this.ringTimeouts = [];
  this.update();
  }
  getDayOfWeek(day) {
  switch (day) {
  case 1:
  return "Monday";
  case 2:
  return "Tuesday";
  case 3:
  return "Wednesday";
  case 4:
  return "Thursday";
  case 5:
  return "Friday";
  case 6:
  return "Saturday";
  default:
  return "Sunday";
  }
  }
  getMonthInfo(mo,yr) {
  switch (mo) {
  case 1:
  return { name: "February", days: yr % 4 === 0 ? 29 : 28 };
  case 2:
  return { name: "March", days: 31 };
  case 3:
  return { name: "April", days: 30 };
  case 4:
  return { name: "May", days: 31 };
  case 5:
  return { name: "June", days: 30 };
  case 6:
  return { name: "July", days: 31 };
  case 7:
  return { name: "August", days: 31 };
  case 8:
  return { name: "September", days: 30 };
  case 9:
  return { name: "October", days: 31 };
  case 10:
  return { name: "November", days: 30 };
  case 11:
  return { name: "December", days: 31 };
  default:
  return { name: "January", days: 31 };
  }
  }
  update() {
  this.time = new Date();

  if (this.el) {
  // date and time
  const dayOfWeek = this.time.getDay();
  const year = this.time.getFullYear();
  const month = this.time.getMonth();
  const day = this.time.getDate();
  const hr = this.time.getHours();
  const min = this.time.getMinutes();
  const sec = this.time.getSeconds();
  const dayOfWeekName = this.getDayOfWeek(dayOfWeek);
  const monthInfo = this.getMonthInfo(month,year);
  const m_progress = sec / 60;
  const h_progress = (min + m_progress) / 60;
  const d_progress = (hr + h_progress) / 24;
  const mo_progress = ((day - 1) + d_progress) / monthInfo.days;
  const units = [
  {
  label: "w",
  value: dayOfWeekName
  },
  {
  label: "mo",
  value: monthInfo.name,
  progress: mo_progress
  },
  {
  label: "d",  
  value: day,
  progress: d_progress
  },
  {
  label: "h",  
  value: hr > 12 ? hr - 12 : hr,
  progress: h_progress
  },
  {
  label: "m",  
  value: min < 10 ? "0" + min : min,
  progress: m_progress
  },
  {
  label: "s",  
  value: sec < 10 ? "0" + sec : sec
  },
  {
  label: "ap",
  value: hr > 12 ? "PM" : "AM"
  }
  ];

  // flush out the timeouts
  this.ringTimeouts.forEach(t => {
  clearTimeout(t);
  });
  this.ringTimeouts = [];

  // update the display
  units.forEach(u => {
  // rings
  const ring = this.el.querySelector(`[data-ring="${u.label}"]`);

  if (ring) {
  const strokeDashArray = ring.getAttribute("stroke-dasharray");
  const fill360 = "progress-clock__ring-fill--360";

  if (strokeDashArray) {
  // calculate the stroke
  const circumference = +strokeDashArray.split(" ")[0];
  const strokeDashOffsetPct = 1 - u.progress;

  ring.setAttribute(
  "stroke-dashoffset",
  strokeDashOffsetPct * circumference
  );

  // add the fade-out transition, then remove it
  if (strokeDashOffsetPct === 1) {
  ring.classList.add(fill360);

  this.ringTimeouts.push(
  setTimeout(() => {
  ring.classList.remove(fill360);
  }, 600)
  );
  }
  }
  }

  // digits
  const unit = this.el.querySelector(`[data-unit="${u.label}"]`);

  if (unit)
  unit.innerText = u.value;
  });
  }

  clearTimeout(this.updateTimeout);
  this.updateTimeout = setTimeout(this.update.bind(this),1e3);
  }
}