CSS Tutorial – A Calendar in Three Lines of CSS

Rengga Dev – This article has no byline and is on a website that is even more weirdly specific than this one is, but I appreciate the trick here. A seven-column grid makes for a calendar layout pretty quick. You can let the days (grid items) fall onto it naturally, except kick the first day over to the correct first column with grid-column-start.

Thoughts:

I’d go with an <ol> rather than a <ul> just because it seems like days are definitely ordered.
The days as-a-list don’t really bother me since maybe that makes semantic sense to the content of the calendar (assuming it has some)
But… seeing the titles of the days-of-the-week as the first items in the same list feels weird. Almost like that should be a separate list or something.
Or maybe it should all just be a <table> since it’s sort of tabular data (it stands to reason you might want to cross-reference and look at all Thursdays or whatever).

Anyway, the placement trickery is fun.

<div class="calendar">
  <header>
    <h1>November 2022</h1>
  </header>

  <ul class="weekdays">
    <li>
      <abbr title="S">Sunday</abbr>
    </li>
    <li>
      <abbr title="M">Monday</abbr>
    </li>
    <li>
      <abbr title="T">Tuesday</abbr>
    </li>
    <li>
      <abbr title="W">Wednesday</abbr>
    </li>
    <li>
      <abbr title="T">Thursday</abbr>
    </li>
    <li>
      <abbr title="F">Friday</abbr>
    </li>
    <li>
      <abbr title="S">Saturday</abbr>
    </li>
  </ul>

  <ol class="day-grid">
    <li class="month=prev">29</li>
    <li class="month=prev">30</li>
    <li class="month=prev">31</li>
    <li>1</li>
    <li>2</li>
    <li>3</li>
    <li>4</li>
    <li>5</li>
    <li>6</li>
    <li>7</li>
    <li>8</li>
    <li>9</li>
    <li>10</li>
    <li>11</li>
    <li>12</li>
    <li>13</li>
    <li>14</li>
    <li>15</li>
    <li>16</li>
    <li>17</li>
    <li>18</li>
    <li>19</li>
    <li>20</li>
    <li>21</li>
    <li>22</li>
    <li>23</li>
    <li>24</li>
    <li>25</li>
    <li>26</li>
    <li>27</li>
    <li>28</li>
    <li>29</li>
    <li>30</li>
    <li class="month-next">1</li>
    <li class="month-next">2</li>
  </ol>
    
</div>

header {
  display: flex;
  align-items: center;
  font-size: calc(16px + (26 - 16) * ((100vw - 300px) / (1600 - 300)));
  justify-content: center;
  margin-bottom: 2em;
  background: #000;
  color: #fff;
  min-height: 10vh;
  text-align: center;
}

ul, ol {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  grid-gap: 1em;
  margin: 0 auto;
  max-width: 64em;
  padding: 0;
}

li {
  display: flex;
  align-items: center;
  justify-content: center;
  list-style: none;
  margin-left: 0;
  font-size: calc(16px + (21 - 16) * ((100vw - 300px) / (1600 - 300)));
}

ul.weekdays {
  margin-bottom: 1em;
}

ul.weekdays li {
  height: 4vw;
}

ol.day-grid li {
  background-color: #eaeaea;
  border: 1px solid #eaeaea;
  height: 12vw;
  max-height: 125px;
}

ul.weekdays abbr[title] {
  border: none;
  font-weight: 800;
  text-decoration: none;
}

ol.day-grid li:nth-child(1),
ol.day-grid li:nth-child(2),
ol.day-grid li:nth-child(3),
ol.day-grid li:nth-child(34),
ol.day-grid li:nth-child(35) {
  background-color: #fff;
}

@media all and (max-width: 800px) {
  ul, ol {
    grid-gap: .25em;
  }
  
  ul.weekdays li {
    font-size: 0;
  }
  
  ul.weekdays > li abbr:after {
      content: attr(title);
      font-size: calc(16px + (26 - 16) * ((100vw - 300px) / (1600 - 300)));
    text-align: center;
    }
}