What is the maximum length of a comet’s tail as seen from Earth?

As you know, the comet’s tail is directed away from the Sun. Therefore, if a comet suddenly finds itself between the Sun and the Earth, and its tail is long and bright enough, its apparent length in the sky will reach 180 °. In this case, the tail will extend from the Sun to the anti-sun point of the sky. Of course, in this case the comet itself will be in conjunction with the Sun and will not be visible. A comet located at an angular distance d from the Sun, the tail length can reach 180 ° -d. The last time a comet with a tail of about 100 ° was observed was in 1996 (comet Hyakutake).