Q: Do we actually have any canon concept of how long Kara was stuck in the Phantom Zone?
[I answered this to a post, and decided the topic was worth its own - slightly edited - posting.]
Whee~ I love turning fictional shows into a science-project!!
So, for how long did Kara stay in the Phantom Zone?
Upfront, the question is a bit misleading, as “time does not exist in the Phantom Zone”. What that means, canonically? Dunno... My head-canon is, that time as a concept is not per se perceivable or at least measurable in the PZ. However, clearly duration exists (a perceived order of events; event A happened before event C and B in the middle - and/or in the absence of events, the ‘sensation’ of un-measurable eternity [and equally nothingness/suddenness]).
However, Kara seems to experience quite a lot of things that are more or less shown to happen parallel to the events on Earth-Prime, which I will use as reference. I looked for mentions of time, daylight / nighttime settings, and wardrobe-changes, based on the assumption that characters (outside of superhero’ing) change their casual wardrobe not more or less than once a day (esp. Lena - at least pre-unemployment - and Andrea). So, here we go:
Any and all references (feel free to comment and add) to passage of time inside the Phantom Zone and on Earth-Prime while Kara was inside the Phantom Zone:
6x01
At the end of the episode, the next morning is shown (considering Andrea only just notices Kara is not there and refers to her father’s financial crash)
Later Lena says about Myriad "[...] I did use it one last time tonight"
only after that, we see Kara waking up (for the first time?) in the PZ
= one whole day has passed (on Earth)
6x02
Starts presumably the same evening (grabbing Silas)
Next morning Nia and William get assigned to Lex's trial, Andrea later visits Lena, Lillian visits Lena, Lena testifies against Lex..
[Aside: We may assume Lex is high-profile enough, his trial is happening a day after he was brought in(?)... is fiction, okay? ...the rushed job may or may not explain the verdict :( ]
Silas did mention it would take him even longer than a week to get his portal working, but he had been talked into trying to get it done by sundown.
And Kelly says “that’s more than anyone could have pulled of in a day” to Alex’s efforts to get Kara back asap.
Kara is rejoined with her father.
...further, judging by everyone's wardrobe:
= one full day passed
6x03
J'onn refers to letting the Phantom into their world / events of 6x02 as "I acted on my emotions yesterday."
Kelly says "Look, I know it's not the same thing but yesterday, when I was in my own despair about what happened at Obsidian..."
Kara says: "Until yesterday, I thought my father was dead."
6x04
Alex sacrificing the crystal to save people over Kara happened within one day
6x05&6x06
3 days passed during Nia and Brainy's time-travel
6x07
2 hours of traveling inside the PZ :P
Kelly, referring to events in 6x03: "Last week, you brought me flowers and asked me to move in with you"
[Aside: We don't know if/when weekends happen, so if let’s say, that episode’s events happened canonically on a Monday, and the referred to events on a Thursday, only like 3-4 days would have passed and the statement of ‘last week’ would still be valid. Either that, or I missed a day or two between 6x04 & the intro of 6x05...]
7 days / one week seems to have passed on Earth.
Kara referring to finding her father possibly matches up (her inner clock may still, at least at the beginning of her stay, have been in tune with the outside world), but cuts may or may not suggest, her subjective “duration” of her stay in the PZ was less long (maybe 3-4 days?), yet at also felt much, much longer...
I hope, that helps, or at least gives some indication as of how to interpret what the show depicted... (although, my personal take is, that the show doesn’t really know itself... soooo....)
[Edit]
I’ve been made aware, that between 6x01 and 6x02 William’s injury seems to have healed - although, that could be a production error. And how both, finding someone with Silas’ skill set and the preparations for Lex’s trial should have taken longer than a day, up to a week.
Usually, an episode of the show spans several days and/or is set about a week after the previous one (x-parters notwithstanding). Technically, this could also have been the case here.
However... Alex’ and Jonnz’ kept depicting urgency, and the way how in the following episodes characters keep referring to previous episodes’ events as “yesterday” implies to me, personally, that events did unfold rather quickly during Kara’s “time” in the Phantom Zone.
If it had been about a week, however, it would mean, that Kara’s perceived time in the Phantom Zone was either even shorter than the time that had passed on Earth-Prime... or she had spent the equivalent of several days getting haunted by Phantoms before Zor-El took her to his cave... - Which I am not against, drama-wise!
(Me thinks, tho, that her “No, no, no, not again!” indicates a 2nd, 3rd or maybe even fourth Phantom-attack, not a several days’ worth - seeing how Phantoms are seen showing up quickly once ppl roam about - after several ‘days’, IMO, she may have reacted much more resigned and less, dare I say, surprised? In my mind, act-first-think-later Kara pretty much spend her first ‘day’ in the PZ actively searching for a way out herself, and therefore somewhat added to her Phantom-encounter-count to merit that reaction... she still appears rather inexperienced and ignorant later when walking outside with others.)
But, again, the characters, their attitudes, how the following episodes seem to tie in back to back with another and by statements made (see above) only so ‘little’ time passed in the rest of the arc, and ...I can find no actual proof for a longer time-span at this or any other point. Meantime: William’s injury had been cauterized, he isn’t seen moving a lot without his arm-sling; Lex is high-profile; M’gann is very well connected in the alien-scene. And most importantly: Can anyone imagine Alex twiddling her thumbs for several days while her sister is in the Phantom Zone?
So, I take the liberty to stick to my above estimate - but feel free to add up to another week to your own count, between 6x01 and 6x02. :)
Also, feel free to convince me and help me get this timeline more accurate! ❤