Calendar component using sveltejs

Calendar.svelte

<script>
    const ONE_DAY = 24*60*60*1000;
    const DAYS = ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"];

    export
    let date, month, year;

    function getCalendar(year, month) {
        var first = new Date(year, month);
        var cells = [];
        var rows = [cells];
        var d = new Date(first.getTime() - ONE_DAY * first.getDay());
        var i = 0;

        for (
            let d = new Date(first.getTime() - ONE_DAY * first.getDay());
            (d.getMonth() <= month && d.getYear() <= year) || i % 7 !== 0 || rows.length < 7;
            d = new Date(d.getTime() + ONE_DAY)
        ) {
            cells.push(d);
            if ((++i % 7) === 0) {
                cells = [];
                rows.push(cells);
            }
        }

        return rows;
    }
</script>

<style>
    table {
        border-collapse: collapse;
    }

    td {
        text-align: center;
        width: 2rem;
        height: 2rem;
        margin: .5rem;
    }
</style>

<table>
    <thead>
        <tr>
        {#each DAYS as day}
                        <th>{day}</th>
        {/each}
        </tr>
    </thead>
    <tbody>
    {#each getCalendar(year,month) as rows}
        <tr>
        {#each rows as cell}
            <td>
            {#if cell.getMonth() === month}
                <a href="javascript:;">
                {#if cell.getDate() === date}
                    <b>{cell.getDate()}</b>
                {:else}
                    {cell.getDate()}
                {/if}
                </a>
            {:else}
                {cell.getDate()}
            {/if}
            </td>
        {/each}
        </tr>
    {/each}
    </tbody>
</table>