UI Components Hard

Date Picker

Calendar date picker with month navigation, range selection, disabled dates, and an input trigger — keyboard accessible.

Open in Lab

css vanilla-js

Targets: JS HTML

Code

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #050910;
  --card: #0d1117;
  --card2: #111827;
  --border: rgba(255, 255, 255, 0.08);
  --text: #f2f6ff;
  --muted: #475569;
  --accent: #38bdf8;
  --accent-bg: rgba(56, 189, 248, 0.14);
  --range-bg: rgba(56, 189, 248, 0.07);
  --today-dot: #38bdf8;
  --radius: 12px;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, sans-serif;
  min-height: 100vh;
  padding: 3rem 1.5rem;
}

.page {
  max-width: 560px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.demo-block {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  position: relative;
}

/* Ensure earlier blocks stack above later ones so popups aren't clipped */
.demo-block:nth-child(1) {
  z-index: 3;
}
.demo-block:nth-child(2) {
  z-index: 2;
}
.demo-block:nth-child(3) {
  z-index: 1;
}

.demo-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--muted);
}

/* ── Input wrap ── */
.dp-wrap,
.dp-range-wrap {
  position: relative;
}

.dp-range-wrap {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.dp-input-wrap {
  position: relative;
  flex: 1;
}

.dp-input {
  width: 100%;
  background: var(--card);
  border: 1.5px solid var(--border);
  color: var(--text);
  padding: 0.6rem 2.5rem 0.6rem 0.875rem;
  border-radius: 10px;
  font-size: 0.875rem;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.dp-input:focus,
.dp-input[aria-expanded="true"] {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.12);
}

.dp-icon {
  position: absolute;
  right: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.9rem;
  pointer-events: none;
  opacity: 0.55;
}

.dp-range-arrow {
  color: var(--muted);
  font-size: 0.85rem;
  flex-shrink: 0;
}

/* ── Calendar popup ── */
.dp-calendar {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  background: var(--card2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.5);
  padding: 1rem;
  min-width: 280px;
  z-index: 500;
  animation: cal-in 0.14s ease;
}

@keyframes cal-in {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.dp-calendar[hidden] {
  display: none;
}

.dp-calendar--range {
  left: 0;
}

/* Inline calendar */
.dp-calendar--inline {
  position: static;
  box-shadow: none;
  border: 1px solid var(--border);
  display: block;
}

.dp-inline {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.dp-inline-value {
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

/* ── Calendar header ── */
.cal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.875rem;
}

.cal-nav-btn {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 1rem;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background 0.2s, border-color 0.2s;
}

.cal-nav-btn:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.2);
}

.cal-month-label {
  font-size: 0.9rem;
  font-weight: 600;
}

/* ── Weekday row ── */
.cal-weekdays {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
  margin-bottom: 4px;
}

.cal-weekday {
  font-size: 0.68rem;
  font-weight: 600;
  text-align: center;
  color: var(--muted);
  padding: 0.2rem 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* ── Days grid ── */
.cal-days {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 2px;
}

.cal-day {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  border-radius: 6px;
  background: none;
  border: none;
  color: var(--text);
  font-size: 0.82rem;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background 0.15s, color 0.15s;
  outline: none;
}

.cal-day:hover:not([disabled]):not(.cal-day--selected):not(.cal-day--selected-end) {
  background: rgba(255, 255, 255, 0.06);
}

.cal-day:focus-visible {
  box-shadow: 0 0 0 2px var(--accent);
}

/* Ghost days (prev/next month) */
.cal-day--ghost {
  color: rgba(71, 85, 105, 0.4);
  cursor: default;
  pointer-events: none;
}

/* Disabled */
.cal-day[disabled] {
  color: rgba(71, 85, 105, 0.35);
  cursor: not-allowed;
  pointer-events: none;
}

/* Today dot */
.cal-day--today::after {
  content: "";
  position: absolute;
  bottom: 3px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 4px;
  background: var(--today-dot);
  border-radius: 50%;
}

/* Selected (single or range endpoints) */
.cal-day--selected,
.cal-day--selected-end {
  background: var(--accent);
  color: #050910;
  font-weight: 700;
}

.cal-day--selected:hover,
.cal-day--selected-end:hover {
  background: var(--accent);
}

/* In-range */
.cal-day--in-range {
  background: var(--range-bg);
  border-radius: 0;
}

/* Range start/end connectors */
.cal-day--selected.cal-day--range-start {
  border-radius: 6px 0 0 6px;
}

.cal-day--selected-end {
  border-radius: 0 6px 6px 0;
}

(function () {
  "use strict";

  const DAYS_OF_WEEK = ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"];
  const MONTHS = [
    "January",
    "February",
    "March",
    "April",
    "May",
    "June",
    "July",
    "August",
    "September",
    "October",
    "November",
    "December",
  ];

  // ── Helpers ─────────────────────────────────────────────────────────────────

  function today() {
    const d = new Date();
    return new Date(d.getFullYear(), d.getMonth(), d.getDate());
  }

  function sameDay(a, b) {
    return a && b && a.toDateString() === b.toDateString();
  }

  function isBefore(a, b) {
    return a && b && a < b;
  }

  function isBetween(d, start, end) {
    if (!start || !end) return false;
    const lo = isBefore(start, end) ? start : end;
    const hi = isBefore(start, end) ? end : start;
    return d > lo && d < hi;
  }

  function formatDate(d) {
    if (!d) return "";
    return d.toLocaleDateString("en-US", { month: "short", day: "numeric", year: "numeric" });
  }

  function daysInMonth(year, month) {
    return new Date(year, month + 1, 0).getDate();
  }

  // ── Calendar builder ─────────────────────────────────────────────────────────

  function buildCalendar(calEl, opts) {
    // opts: { year, month, selected, rangeStart, rangeEnd, hoverDate, onSelect, onHover, disablePast }
    calEl.innerHTML = "";

    const year = opts.year;
    const month = opts.month;
    const firstDay = new Date(year, month, 1).getDay(); // 0 = Sunday
    const totalDays = daysInMonth(year, month);
    const now = today();

    // Header
    const header = el("div", "cal-header");
    const prevBtn = el("button", "cal-nav-btn");
    prevBtn.innerHTML = "‹";
    prevBtn.setAttribute("aria-label", "Previous month");
    prevBtn.addEventListener("click", function () {
      opts.onMonthChange(-1);
    });

    const nextBtn = el("button", "cal-nav-btn");
    nextBtn.innerHTML = "›";
    nextBtn.setAttribute("aria-label", "Next month");
    nextBtn.addEventListener("click", function () {
      opts.onMonthChange(1);
    });

    const label = el("span", "cal-month-label");
    label.textContent = MONTHS[month] + " " + year;

    header.appendChild(prevBtn);
    header.appendChild(label);
    header.appendChild(nextBtn);
    calEl.appendChild(header);

    // Weekdays
    const wdRow = el("div", "cal-weekdays");
    DAYS_OF_WEEK.forEach(function (d) {
      const wd = el("span", "cal-weekday");
      wd.textContent = d;
      wdRow.appendChild(wd);
    });
    calEl.appendChild(wdRow);

    // Days
    const grid = el("div", "cal-days");

    // Ghost days from prev month
    const prevMonthDays = daysInMonth(year, month - 1);
    for (let i = firstDay - 1; i >= 0; i--) {
      const ghost = el("button", "cal-day cal-day--ghost");
      ghost.textContent = prevMonthDays - i;
      ghost.disabled = true;
      grid.appendChild(ghost);
    }

    // Real days
    for (let d = 1; d <= totalDays; d++) {
      const date = new Date(year, month, d);
      const btn = el("button", "cal-day");
      btn.textContent = d;
      btn.setAttribute("data-date", date.toISOString());
      btn.setAttribute("aria-label", formatDate(date));

      // Today
      if (sameDay(date, now)) btn.classList.add("cal-day--today");

      // Disabled (past dates)
      if (opts.disablePast && date < now) {
        btn.disabled = true;
        btn.classList.add("cal-day--disabled");
      }

      // Selected single
      if (!opts.rangeStart && sameDay(date, opts.selected)) {
        btn.classList.add("cal-day--selected");
      }

      // Range: start
      if (opts.rangeStart && sameDay(date, opts.rangeStart)) {
        btn.classList.add("cal-day--selected", "cal-day--range-start");
      }

      // Range: end
      const effectiveEnd = opts.rangeEnd || opts.hoverDate;
      if (
        opts.rangeStart &&
        effectiveEnd &&
        sameDay(date, effectiveEnd) &&
        !sameDay(date, opts.rangeStart)
      ) {
        btn.classList.add("cal-day--selected-end");
      }

      // Range: in-between
      if (opts.rangeStart && isBetween(date, opts.rangeStart, effectiveEnd)) {
        btn.classList.add("cal-day--in-range");
      }

      btn.addEventListener("click", function () {
        if (opts.onSelect) opts.onSelect(date);
      });

      if (opts.onHover) {
        btn.addEventListener("mouseenter", function () {
          opts.onHover(date);
        });
      }

      grid.appendChild(btn);
    }

    // Ghost days for next month to fill the grid
    const totalCells = Math.ceil((firstDay + totalDays) / 7) * 7;
    for (let i = 1; i <= totalCells - firstDay - totalDays; i++) {
      const ghost = el("button", "cal-day cal-day--ghost");
      ghost.textContent = i;
      ghost.disabled = true;
      grid.appendChild(ghost);
    }

    calEl.appendChild(grid);
  }

  function el(tag, cls) {
    const e = document.createElement(tag);
    if (cls) e.className = cls;
    return e;
  }

  // ── Demo 1: Single date picker ───────────────────────────────────────────────

  (function () {
    const input = document.getElementById("single-input");
    const calEl = document.getElementById("cal-single");
    const wrap = document.getElementById("dp-single");
    let open = false;
    let selected = null;
    let viewYear = today().getFullYear();
    let viewMonth = today().getMonth();

    function render() {
      buildCalendar(calEl, {
        year: viewYear,
        month: viewMonth,
        selected: selected,
        disablePast: false,
        onMonthChange: function (d) {
          viewMonth += d;
          if (viewMonth > 11) {
            viewMonth = 0;
            viewYear++;
          }
          if (viewMonth < 0) {
            viewMonth = 11;
            viewYear--;
          }
          render();
        },
        onSelect: function (date) {
          selected = date;
          input.value = formatDate(date);
          close();
        },
      });
    }

    function open_() {
      open = true;
      calEl.removeAttribute("hidden");
      input.setAttribute("aria-expanded", "true");
      render();
    }

    function close() {
      open = false;
      calEl.setAttribute("hidden", "");
      input.setAttribute("aria-expanded", "false");
    }

    input.addEventListener("click", function () {
      open ? close() : open_();
    });
    input.addEventListener("keydown", function (e) {
      if (e.key === "Enter" || e.key === " ") {
        e.preventDefault();
        open ? close() : open_();
      }
      if (e.key === "Escape") close();
    });

    document.addEventListener("click", function (e) {
      if (!wrap.contains(e.target)) close();
    });
  })();

  // ── Demo 2: Date range picker ────────────────────────────────────────────────

  (function () {
    const startInput = document.getElementById("range-start");
    const endInput = document.getElementById("range-end");
    const calEl = document.getElementById("cal-range");
    const wrap = document.getElementById("dp-range");

    let open = false;
    let rangeStart = null;
    let rangeEnd = null;
    let hoverDate = null;
    let picking = "start"; // "start" | "end"
    let viewYear = today().getFullYear();
    let viewMonth = today().getMonth();

    function render() {
      buildCalendar(calEl, {
        year: viewYear,
        month: viewMonth,
        rangeStart: rangeStart,
        rangeEnd: rangeEnd,
        hoverDate: hoverDate,
        disablePast: false,
        onMonthChange: function (d) {
          viewMonth += d;
          if (viewMonth > 11) {
            viewMonth = 0;
            viewYear++;
          }
          if (viewMonth < 0) {
            viewMonth = 11;
            viewYear--;
          }
          render();
        },
        onSelect: function (date) {
          if (picking === "start") {
            rangeStart = date;
            rangeEnd = null;
            picking = "end";
            startInput.value = formatDate(date);
            endInput.value = "";
          } else {
            // If end before start, swap
            if (date < rangeStart) {
              rangeEnd = rangeStart;
              rangeStart = date;
            } else {
              rangeEnd = date;
            }
            picking = "start";
            startInput.value = formatDate(rangeStart);
            endInput.value = formatDate(rangeEnd);
            close();
          }
          render();
        },
        onHover: function (date) {
          if (picking === "end") {
            hoverDate = date;
            render();
          }
        },
      });
    }

    function open_() {
      open = true;
      calEl.removeAttribute("hidden");
      render();
    }

    function close() {
      open = false;
      calEl.setAttribute("hidden", "");
    }

    [startInput, endInput].forEach(function (inp) {
      inp.addEventListener("click", function () {
        open ? close() : open_();
      });
    });

    document.addEventListener("click", function (e) {
      if (!wrap.contains(e.target)) close();
    });
  })();

  // ── Demo 3: Inline calendar ──────────────────────────────────────────────────

  (function () {
    const calEl = document.getElementById("cal-inline");
    const valueEl = document.getElementById("inline-value");
    let selected = null;
    let viewYear = today().getFullYear();
    let viewMonth = today().getMonth();

    function render() {
      buildCalendar(calEl, {
        year: viewYear,
        month: viewMonth,
        selected: selected,
        disablePast: false,
        onMonthChange: function (d) {
          viewMonth += d;
          if (viewMonth > 11) {
            viewMonth = 0;
            viewYear++;
          }
          if (viewMonth < 0) {
            viewMonth = 11;
            viewYear--;
          }
          render();
        },
        onSelect: function (date) {
          selected = date;
          valueEl.textContent = "Selected: " + formatDate(date);
          render();
        },
      });
    }

    render();
  })();
})();

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Date Picker</title>
  <link rel="stylesheet" href="style.css" />
</head>
<body>

  <div class="page">

    <!-- ── Demo 1: Single date picker ── -->
    <div class="demo-block">
      <label class="demo-label" for="single-input">Single date picker</label>
      <div class="dp-wrap" id="dp-single">
        <div class="dp-input-wrap">
          <input
            type="text"
            id="single-input"
            class="dp-input"
            placeholder="Select a date…"
            readonly
            aria-haspopup="true"
            aria-expanded="false"
            aria-label="Date picker"
          />
          <span class="dp-icon" aria-hidden="true">📅</span>
        </div>
        <div class="dp-calendar" id="cal-single" role="dialog" aria-label="Date picker calendar" hidden></div>
      </div>
    </div>

    <!-- ── Demo 2: Date range picker ── -->
    <div class="demo-block">
      <label class="demo-label">Date range picker</label>
      <div class="dp-range-wrap" id="dp-range">
        <div class="dp-input-wrap">
          <input
            type="text"
            id="range-start"
            class="dp-input dp-input--range"
            placeholder="Start date…"
            readonly
            aria-label="Range start date"
          />
          <span class="dp-icon" aria-hidden="true">📅</span>
        </div>
        <span class="dp-range-arrow" aria-hidden="true">→</span>
        <div class="dp-input-wrap">
          <input
            type="text"
            id="range-end"
            class="dp-input dp-input--range"
            placeholder="End date…"
            readonly
            aria-label="Range end date"
          />
          <span class="dp-icon" aria-hidden="true">📅</span>
        </div>
        <div class="dp-calendar dp-calendar--range" id="cal-range" role="dialog" aria-label="Date range calendar" hidden></div>
      </div>
    </div>

    <!-- ── Demo 3: Inline calendar ── -->
    <div class="demo-block">
      <p class="demo-label">Inline calendar</p>
      <div class="dp-inline" id="dp-inline">
        <div class="dp-calendar dp-calendar--inline" id="cal-inline"></div>
        <p class="dp-inline-value" id="inline-value">No date selected</p>
      </div>
    </div>

  </div>

  <script src="script.js"></script>
</body>
</html>

Date Picker

A full calendar date picker with month navigation, single-date and range selection, disabled past dates, and an inline variant. No external libraries.

Variants

Single date — click an input to open a calendar dropdown, select a date, input updates
Date range — two inputs (start / end); first click sets start, second click sets end, hover highlights the range
Inline calendar — always visible, no trigger input

How it works

The calendar grid is generated dynamically: first-day offset + days-in-month cells, padded with previous/next month ghost days
Month navigation arrows call changeMonth(delta) which re-renders the grid
For range mode, two state variables track rangeStart and rangeEnd; mouseover on a day cell updates a hoverDate used for the in-range highlight
Past dates receive the disabled attribute and class; they are skipped during keyboard navigation
Arrow keys move focus cell-by-cell; Enter selects; Escape closes the dropdown

Day cell states

Today — dot indicator below the number
Selected / range endpoints — solid accent background
In-range — light accent tint background
Disabled — muted text, not interactive