As any popular science reader knows, when traveling between Earth and Mars,
there's a Hohmann transfer opportunity about every two years (I believe it's every 26 months, specifically).
What I've never understood or seen mentioned, what is the reasonable realistic window for that - as actually used in practice by NASA / Rosaviakosmos / CNSA / ISRO / ESA ...
You're getting ready to do a Hohmann transfer (in either direction!).
Do you have only a matter of minutes? Hours? Days? A couple of months? ...
to really enjoy the Hohmann transfer?
Are there some practical examples of past launches? (So, "On blah blah mission, realistically we had about X days on either side to leave Earth orbit...")
I might point out that this is one of those annoying questions that is probably really obvious to experts who do these calculations every day, and the answer might be as simple as "well it's a blah or two". Cheers