Timeline
Year 1
Summer: Episode 1 - 14
December To February
One and two are introduction episodes, and therefore don’t connect to any episodes. Three - five take place chronologically after each other, with no break to the story flow. Six and seven are connected as the Miso soup in six results in the events of seven. Eight and nine are about Tansho, but how close the two episodes happen to one another is up to anyone's guess, but it does happen within summer.
10 and 11 work in tandem, as the beach visit could lead to Mara getting sick and then being nursed by Yuri. 12, 13 and 14 are detached from each other, except for their shared season.
Autumn: Episode 15 - 21
March To May
Since there seem to be similarities between the human and elven world, we assume that the school year starts in April, which puts 15 in autumn, as we hear of Umamani’s enrollment in school from Funou. 16, 17 and 18 are detached stories that happen before school resumes.
19 - 21 would function as a one day event, with 19 in the morning at school start, where Yuri and Mara meet Umanami for the first time. 20 would be in the middle of the day, with Tansho and Yuri running into Shinsei from the disciplinary, and then later in the evening we see Mara and Tansho surprise Yuri with Halloween costumes. All these episodes are in a relatively warm season, but not like how episodes 1 - 14 were.
Winter: Episode 22
June To August
22 is the only episode with a winter like setting, with 21 and 23 both having warmer weather than peak winter cold, as shown in 22. 24 hints that 23 takes place near the end of winter, since the two episodes are close to one another timewise.
Spring: Episode 23 - 25
September To October
23 and 24 happen on the same day, as Yuri wears the same attire in both. 23 takes place in the morning, and then Yuri meets up with Tansho later to pick a Halloween costume. 25 and 26 are in different seasons as the attire changes up considerably.
Year 2
Summer: Episode 26 - Ongoing
December To February
26 and 27 could take place in one day, as it’d fit into an arc with 28. The two episodes in school on a Friday, and then Yuri, Umanami, AV and Funou at the beach on the weekend in 28. 29 to 31 would function as a one day event. Tansho gets help from Yuri in the morning, Mara and Tansho then go home for New Year’s Eve. 30 happens after Yuri takes a small shower, and then AV-san arrives to scout her before the evening festivities. 31 then happens on New Year’s Eve itself.
32 is said to take place a few days after 31 by Umanami, and 33 a short while after that as Mara says Umanami has been bragging about her relationship with Yuri. Episode 34 most likely takes place a few weeks, to a month, after New Year’s Eve, and around the same time they first visited the ocean.