请帮我猜一猜这个字谜：

日！ 画时圆（画画时圆的太阳就是“日”）,写时方（“日”写着就是方方正正）,冬天短（冬天太阳日照时间短）,夏天长（夏天日照时间长）,冬海有条鱼,没头没尾,抽出脊梁骨（“鱼字”去头，去底下，再去掉中间的一竖，就是“日”）

太阳

Paintings circle (drawing a circle when the sun is the "Day"), written when the party (the "Day" is written just like they should), the winter short (the winter sun, sunshine time is short), the summer long (longer in summer sunshine), Winter sea a fish, no head no tail, taking the spine ( "fish word" go head, go to the bottom, and then remove the pricked the middle is the "Day")

我们书上是日。因为画的时候是圆的，写的时候是方的，冬天日照时间较短，夏天日照时间较长 也可以说是太阳，不过这是字谜……是“字”