Using javascript, change the background of <code><body></code> to <code>hsl(N,50%,97%)</code> where N is determined according to this algorithm:

<pre><code>(define (seasonal-hue day-of-year)
  (define t1 (if (> day-of-year 359) 0 day-of-year))
  (define t2 (- 240 t1))
  (if (> 0 t2) (+ 360 t2) t2))


In this way, Jan 1 occurs in the blue area of the HSL color wheel, and the value moves counterclockwise through green, yellow, orange, red, magenta, purple as the year progresses.

In the same script, set some text in a corner somewhere to match one of <a 72 Japanese microseasons</a>:

<table class="txt11">  <tbody>  <tr>  <th colspan="3">立春 <em>Risshun</em> (Beginning of spring)</th>  </tr>  <tr>  <td class="second_color">February 4–8</td>  <td>東風解凍  <em>Harukaze kōri o <td>East wind melts the ice</td>  </tr>  <tr>  <td class="second_color">February 9–13</td>  <td>黄鶯睍睆  <em>Kōō kenkan <td>Bush warblers start singing in the mountains</td>  </tr>  <tr>  <td class="second_color">February 14–18</td>  <td>魚上氷  <em>Uo kōri o <td>Fish emerge from the ice</td>  </tr>  <tr>  <th colspan="3">雨水 <em>Usui</em> (Rainwater)</th>  </tr>  <tr>  <td class="second_color">February 19–23</td>  <td>土脉潤起  <em>Tsuchi no shō uruoi <td>Rain moistens the soil</td>  </tr>  <tr>  <td class="second_color">February 24–28</td>  <td>霞始靆  <em>Kasumi hajimete <td>Mist starts to linger</td>  </tr>  <tr>  <td class="second_color">March 1–5</td>  <td>草木萌動  <em>Sōmoku mebae <td>Grass sprouts, trees bud</td>  </tr>  <tr>  <th colspan="3">啓蟄 <em>Keichitsu</em> (Insects awaken)</th>  </tr>  <tr>  <td class="second_color">March 6–10</td>  <td>蟄虫啓戸  <em>Sugomori mushito o <td>Hibernating insects surface</td>  </tr>  <tr>  <td class="second_color">March 11–15</td>  <td>桃始笑  <em>Momo hajimete <td>First peach blossoms</td>  </tr>  <tr>  <td class="second_color">March 16–20</td>  <td>菜虫化蝶  <em>Namushi chō to <td>Caterpillars become butterflies</td>  </tr>  <tr>  <th colspan="3">春分 <em>Shunbun</em> (Spring equinox)</th>  </tr>  <tr>  <td class="second_color">March 21–25</td>  <td>雀始巣  <em>Suzume hajimete <td>Sparrows start to nest</td>  </tr>  <tr>  <td class="second_color">March 26–30</td>  <td>櫻始開  <em>Sakura hajimete <td>First cherry blossoms</td>  </tr>  <tr>  <td class="second_color">March 31–April 4</td>  <td>雷乃発声  <em>Kaminari sunawachi koe o <td>Distant thunder</td>  </tr>  <tr>  <th colspan="3">清明 <em>Seimei</em> (Pure and clear)</th>  </tr>  <tr>  <td class="second_color">April 5–9</td>  <td>玄鳥至  <em>Tsubame <td>Swallows return</td>  </tr>  <tr>  <td class="second_color">April 10–14</td>  <td>鴻雁北  <em>Kōgan <td>Wild geese fly north</td>  </tr>  <tr>  <td class="second_color">April 15–19</td>  <td>虹始見  <em>Niji hajimete <td>First rainbows</td>  </tr>  <tr>  <th colspan="3">穀雨 <em>Kokuu</em> (Grain rains)</th>  </tr>  <tr>  <td class="second_color">April 20–24</td>  <td>葭始生  <em>Ashi hajimete <td>First reeds sprout</td>  </tr>  <tr>  <td class="second_color">April 25–29</td>  <td>霜止出苗  <em>Shimo yamite nae <td>Last frost, rice seedlings grow</td>  </tr>  <tr>  <td class="second_color">April 30–May 4</td>  <td>牡丹華  <em>Botan hana <td>Peonies bloom</td>  </tr>  <tr>  <th colspan="3">立夏 <em>Rikka</em> (Beginning of summer)</th>  </tr>  <tr>  <td class="second_color">May 5–9</td>  <td>蛙始鳴  <em>Kawazu hajimete <td>Frogs start singing</td>  </tr>  <tr>  <td class="second_color">May 10–14</td>  <td>蚯蚓出  <em>Mimizu <td>Worms surface</td>  </tr>  <tr>  <td class="second_color">May 15–20</td>  <td>竹笋生  <em>Takenoko <td>Bamboo shoots sprout</td>  </tr>  <tr>  <th colspan="3">小満 <em>Shōman</em> (Lesser ripening)</th>  </tr>  <tr>  <td class="second_color">May 21–25</td>  <td>蚕起食桑  <em>Kaiko okite kuwa o <td>Silkworms start feasting on mulberry leaves</td>  </tr>  <tr>  <td class="second_color">May 26–30</td>  <td>紅花栄  <em>Benibana <td>Safflowers bloom</td>  </tr>  <tr>  <td class="second_color">May 31–June 5</td>  <td>麦秋至  <em>Mugi no toki <td>Wheat ripens and is harvested</td>  </tr>  <tr>  <th colspan="3">芒種 <em>Bōshu</em> (Grain beards and seeds)</th>  </tr>  <tr>  <td class="second_color">June 6–10</td>  <td>蟷螂生  <em>Kamakiri <td>Praying mantises hatch</td>  </tr>  <tr>  <td class="second_color">June 11–15</td>  <td>腐草為螢  <em>Kusaretaru kusa hotaru to <td>Rotten grass becomes fireflies</td>  </tr>  <tr>  <td class="second_color">June 16–20</td>  <td>梅子黄  <em>Ume no mi <td>Plums turn yellow</td>  </tr>  <tr>  <th colspan="3">夏至 <em>Geshi</em> (Summer solstice)</th>  </tr>  <tr>  <td class="second_color">June 21–26</td>  <td>乃東枯  <em>Natsukarekusa <td>Self-heal withers</td>  </tr>  <tr>  <td class="second_color">June 27–July 1</td>  <td>菖蒲華  <em>Ayame hana <td>Irises bloom</td>  </tr>  <tr>  <td class="second_color">July 2–6</td>  <td>半夏生  <em>Hange <td>Crow-dipper sprouts</td>  </tr>  <tr>  <th colspan="3">小暑 <em>Shōsho</em> (Lesser heat)</th>  </tr>  <tr>  <td class="second_color">July 7–11</td>  <td>温風至  <em>Atsukaze <td>Warm winds blow</td>  </tr>  <tr>  <td class="second_color">July 12–16</td>  <td>蓮始開  <em>Hasu hajimete <td>First lotus blossoms</td>  </tr>  <tr>  <td class="second_color">July 17–22</td>  <td>鷹乃学習  <em>Taka sunawachi waza o <td>Hawks learn to fly</td>  </tr>  <tr>  <th colspan="3">大暑 <em>Taisho</em> (Greater heat)</th>  </tr>  <tr>  <td class="second_color">July 23–28</td>  <td>桐始結花  <em>Kiri hajimete hana o <td>Paulownia trees produce seeds</td>  </tr>  <tr>  <td class="second_color">July 29–August 2</td>  <td>土潤溽暑  <em>Tsuchi uruōte mushi <td>Earth is damp, air is humid</td>  </tr>  <tr>  <td class="second_color">August 3–7</td>  <td>大雨時行  <em>Taiu tokidoki <td>Great rains sometimes fall</td>  </tr>  <tr>  <th colspan="3">立秋 <em>Risshū</em> (Beginning of autumn)</th>  </tr>  <tr>  <td class="second_color">August 8–12</td>  <td>涼風至  <em>Suzukaze <td>Cool winds blow</td>  </tr>  <tr>  <td class="second_color">August 13–17</td>  <td>寒蝉鳴  <em>Higurashi <td>Evening cicadas sing</td>  </tr>  <tr>  <td class="second_color">August 18–22</td>  <td>蒙霧升降  <em>Fukaki kiri <td>Thick fog descends</td>  </tr>  <tr>  <th colspan="3">処暑 <em>Shosho</em> (Manageable heat)</th>  </tr>  <tr>  <td class="second_color">August 23–27</td>  <td>綿柎開  <em>Wata no hana shibe <td>Cotton flowers bloom</td>  </tr>  <tr>  <td class="second_color">August 28–September 1</td>  <td>天地始粛  <em>Tenchi hajimete <td>Heat starts to die down</td>  </tr>  <tr>  <td class="second_color">September 2–7</td>  <td>禾乃登  <em>Kokumono sunawachi <td>Rice ripens</td>  </tr>  <tr>  <th colspan="3">白露 <em>Hakuro</em> (White dew)</th>  </tr>  <tr>  <td class="second_color">September 8–12</td>  <td>草露白  <em>Kusa no tsuyu <td>Dew glistens white on grass</td>  </tr>  <tr>  <td class="second_color">September 13–17</td>  <td>鶺鴒鳴  <em>Sekirei <td>Wagtails sing</td>  </tr>  <tr>  <td class="second_color">September 18–22</td>  <td>玄鳥去  <em>Tsubame <td>Swallows leave</td>  </tr>  <tr>  <th colspan="3">秋分 <em>Shūbun</em> (Autumn equinox)</th>  </tr>  <tr>  <td class="second_color">September 23–27</td>  <td>雷乃収声  <em>Kaminari sunawachi koe o <td>Thunder ceases</td>  </tr>  <tr>  <td class="second_color">September 28–October 2</td>  <td>蟄虫坏戸  <em>Mushi kakurete to o <td>Insects hole up underground</td>  </tr>  <tr>  <td class="second_color">October 3–7</td>  <td>水始涸  <em>Mizu hajimete <td>Farmers drain fields</td>  </tr>  <tr>  <th colspan="3">寒露 <em>Kanro</em> (Cold dew)</th>  </tr>  <tr>  <td class="second_color">October 8–12</td>  <td>鴻雁来  <em>Kōgan <td>Wild geese return</td>  </tr>  <tr>  <td class="second_color">October 13–17</td>  <td>菊花開  <em>Kiku no hana <td>Chrysanthemums bloom</td>  </tr>  <tr>  <td class="second_color">October 18–22</td>  <td>蟋蟀在戸  <em>Kirigirisu to ni <td>Crickets chirp around the door</td>  </tr>  <tr>  <th colspan="3">霜降 <em>Sōkō</em> (Frost falls)</th>  </tr>  <tr>  <td class="second_color">October 23–27</td>  <td>霜始降  <em>Shimo hajimete <td>First frost</td>  </tr>  <tr>  <td class="second_color">October 28–November 1</td>  <td>霎時施  <em>Kosame tokidoki <td>Light rains sometimes fall</td>  </tr>  <tr>  <td class="second_color">November 2–6</td>  <td>楓蔦黄  <em>Momiji tsuta <td>Maple leaves and ivy turn yellow</td>  </tr>  <tr>  <th colspan="3">立冬 <em>Rittō</em> (Beginning of winter)</th>  </tr>  <tr>  <td class="second_color">November 7–11</td>  <td>山茶始開  <em>Tsubaki hajimete <td>Camellias bloom</td>  </tr>  <tr>  <td class="second_color">November 12–16</td>  <td>地始凍  <em>Chi hajimete <td>Land starts to freeze</td>  </tr>  <tr>  <td class="second_color">November 17–21</td>  <td>金盞香  <em>Kinsenka <td>Daffodils bloom</td>  </tr>  <tr>  <th colspan="3">小雪 <em>Shōsetsu</em> (Lesser snow)</th>  </tr>  <tr>  <td class="second_color">November 22–26</td>  <td>虹蔵不見  <em>Niji kakurete <td>Rainbows hide</td>  </tr>  <tr>  <td class="second_color">November 27–December 1</td>  <td>朔風払葉  <em>Kitakaze konoha o <td>North wind blows the leaves from the trees</td>  </tr>  <tr>  <td class="second_color">December 2–6</td>  <td>橘始黄  <em>Tachibana hajimete <td><em>Tachibana</em> citrus tree leaves start to turn yellow</td>  </tr>  <tr>  <th colspan="3">大雪 <em>Taisetsu</em> (Greater snow)</th>  </tr>  <tr>  <td class="second_color">December 7–11</td>  <td>閉塞成冬  <em>Sora samuku fuyu to <td>Cold sets in, winter begins</td>  </tr>  <tr>  <td class="second_color">December 12–16</td>  <td>熊蟄穴  <em>Kuma ana ni <td>Bears start hibernating in their dens</td>  </tr>  <tr>  <td class="second_color">December 17–21</td>  <td>鱖魚群  <em>Sake no uo <td>Salmons gather and swim upstream</td>  </tr>  <tr>  <th colspan="3">冬至 <em>Tōji</em> (Winter solstice)</th>  </tr>  <tr>  <td class="second_color">December 22–26</td>  <td>乃東生  <em>Natsukarekusa <td>Self-heal sprouts</td>  </tr>  <tr>  <td class="second_color">December 27–31</td>  <td>麋角解  <em>Sawashika no tsuno <td>Deer shed antlers</td>  </tr>  <tr>  <td class="second_color">January 1–4</td>  <td>雪下出麦  <em>Yuki watarite mugi <td>Wheat sprouts under snow</td>  </tr>  <tr>  <th colspan="3">小寒 <em>Shōkan</em> (Lesser cold)</th>  </tr>  <tr>  <td class="second_color">January 5–9</td>  <td>芹乃栄  <em>Seri sunawachi <td>Parsley flourishes</td>  </tr>  <tr>  <td class="second_color">January 10–14</td>  <td>水泉動  <em>Shimizu atataka o <td>Springs thaw</td>  </tr>  <tr>  <td class="second_color">January 15–19</td>  <td>雉始雊  <em>Kiji hajimete <td>Pheasants start to call</td>  </tr>  <tr>  <th colspan="3">大寒 <em>Daikan</em> (Greater cold)</th>  </tr>  <tr>  <td class="second_color">January 20–24</td>  <td>款冬華  <em>Fuki no hana <td>Butterburs bud</td>  </tr>  <tr>  <td class="second_color">January 25–29</td>  <td>水沢腹堅  <em>Kiwamizu kōri <td>Ice thickens on streams</td>  </tr>  <tr>  <td class="second_color">January 30–February 3</td>  <td>鶏始乳  <em>Niwatori hajimete toya ni <td>Hens start laying eggs</td>  </tr>  </tbody>  </table>