Farnsworth laments the idea of producing a three-month calendar, saying "What is this? Mercury?!" Mercury indeed makes a full revolution of the sun in only 88 Earth days, just under three months.
The end credits feature a number of images, presumably from the Planet Express pinup calendar, that features the gender-switched men posing provocatively in their female form. The images can be seen on DVD and digital download, but have rarely aired on television because the credits are usually skipped or sped up.
Gender, and more specifically biological sex, are central themes to the episode. As a result, many structures and objects were intentionally designed to resemble male and female anatomy. There are several prominent phallic symbols and several objects that resemble female genitalia and reproductive organs. One joke of this nature features the men getting lost on the rock planet in a valley that resembles female genitalia.
When the company is converted into an airline, it's renamed "Plan-Am" - a reference both to its former name "Planet Express", and the iconic US airline "Pan-Am".
One of the rock aliens is called the Borax Kid, whose white color and physical appearance matches that of the boron-based mineral called borax.