Maybe, it's just a date/timezone configuration.

Here is the API response
for watched show progress:
{
"aired": 43,
"completed": 42,
"last_watched_at": "2017-05-27T23:00:15.000Z",
"seasons": [
{
"number": 1,
"aired": 20,
"completed": 20,
"episodes": [
{
"number": 1,
"completed": true,
"last_watched_at": "2015-10-27T18:52:45.000Z"
},
{
"number": 2,
"completed": true,
"last_watched_at": "2015-11-06T03:56:12.000Z"
},
{
"number": 3,
"completed": true,
"last_watched_at": "2015-11-12T02:09:24.000Z"
},
{
"number": 4,
"completed": true,
"last_watched_at": "2015-11-19T16:18:02.000Z"
},
{
"number": 5,
"completed": true,
"last_watched_at": "2015-11-26T03:39:29.000Z"
},
{
"number": 6,
"completed": true,
"last_watched_at": "2015-12-02T16:42:56.000Z"
},
{
"number": 7,
"completed": true,
"last_watched_at": "2015-12-10T01:27:04.000Z"
},
{
"number": 8,
"completed": true,
"last_watched_at": "2015-12-19T17:41:51.000Z"
},
{
"number": 9,
"completed": true,
"last_watched_at": "2016-01-27T23:00:49.000Z"
},
{
"number": 10,
"completed": true,
"last_watched_at": "2016-01-27T23:00:55.000Z"
},
{
"number": 11,
"completed": true,
"last_watched_at": "2016-01-28T22:36:21.000Z"
},
{
"number": 12,
"completed": true,
"last_watched_at": "2016-02-06T21:13:49.000Z"
},
{
"number": 13,
"completed": true,
"last_watched_at": "2016-02-13T19:53:58.000Z"
},
{
"number": 14,
"completed": true,
"last_watched_at": "2016-02-28T18:46:29.000Z"
},
{
"number": 15,
"completed": true,
"last_watched_at": "2016-03-14T03:56:57.000Z"
},
{
"number": 16,
"completed": true,
"last_watched_at": "2016-03-26T03:12:17.000Z"
},
{
"number": 17,
"completed": true,
"last_watched_at": "2016-03-26T20:48:01.000Z"
},
{
"number": 18,
"completed": true,
"last_watched_at": "2016-05-14T01:49:01.000Z"
},
{
"number": 19,
"completed": true,
"last_watched_at": "2016-05-20T01:36:35.000Z"
},
{
"number": 20,
"completed": true,
"last_watched_at": "2016-05-21T19:38:53.000Z"
}
]
},
{
"number": 2,
"aired": 22,
"completed": 22,
"episodes": [
{
"number": 1,
"completed": true,
"last_watched_at": "2016-10-30T22:43:40.000Z"
},
{
"number": 2,
"completed": true,
"last_watched_at": "2016-11-01T00:59:15.000Z"
},
{
"number": 3,
"completed": true,
"last_watched_at": "2016-11-02T01:48:20.000Z"
},
{
"number": 4,
"completed": true,
"last_watched_at": "2016-11-06T17:49:08.000Z"
},
{
"number": 5,
"completed": true,
"last_watched_at": "2016-11-15T17:04:41.000Z"
},
{
"number": 6,
"completed": true,
"last_watched_at": "2016-11-16T23:46:13.000Z"
},
{
"number": 7,
"completed": true,
"last_watched_at": "2016-11-27T16:03:17.000Z"
},
{
"number": 8,
"completed": true,
"last_watched_at": "2016-11-29T01:00:00.000Z"
},
{
"number": 9,
"completed": true,
"last_watched_at": "2017-01-29T02:05:20.000Z"
},
{
"number": 10,
"completed": true,
"last_watched_at": "2017-02-12T03:33:25.000Z"
},
{
"number": 11,
"completed": true,
"last_watched_at": "2017-02-12T20:47:46.000Z"
},
{
"number": 12,
"completed": true,
"last_watched_at": "2017-03-10T00:33:24.000Z"
},
{
"number": 13,
"completed": true,
"last_watched_at": "2017-03-11T04:46:38.000Z"
},
{
"number": 14,
"completed": true,
"last_watched_at": "2017-03-11T19:46:20.000Z"
},
{
"number": 15,
"completed": true,
"last_watched_at": "2017-03-11T21:03:01.000Z"
},
{
"number": 16,
"completed": true,
"last_watched_at": "2017-03-28T02:12:24.000Z"
},
{
"number": 17,
"completed": true,
"last_watched_at": "2017-04-03T02:32:17.000Z"
},
{
"number": 18,
"completed": true,
"last_watched_at": "2017-05-01T22:52:27.000Z"
},
{
"number": 19,
"completed": true,
"last_watched_at": "2017-05-12T01:38:08.000Z"
},
{
"number": 20,
"completed": true,
"last_watched_at": "2017-05-13T00:30:06.000Z"
},
{
"number": 21,
"completed": true,
"last_watched_at": "2017-05-21T00:33:15.000Z"
},
{
"number": 22,
"completed": true,
"last_watched_at": "2017-05-27T23:00:15.000Z"
}
]
},
{
"number": 3,
"aired": 1,
"completed": 0,
"episodes": [
{
"number": 1,
"completed": false,
"last_watched_at": null
}
]
}
],
"hidden_seasons": [],
"next_episode": {
"season": 3,
"number": 1,
"title": "Girl of Steel",
"ids": {
"trakt": 2605191,
"tvdb": 6124745,
"imdb": "tt6403442",
"tmdb": 1337377,
"tvrage": 0
}
},
"last_episode": {
"season": 2,
"number": 22,
"title": "Nevertheless, She Persisted",
"ids": {
"trakt": 2492115,
"tvdb": 6043967,
"imdb": "tt5827214",
"tmdb": 1311089,
"tvrage": 0
}
}
}
and for episode summary:
{
"season": 3,
"number": 1,
"title": "Girl of Steel",
"ids": {
"trakt": 2605191,
"tvdb": 6124745,
"imdb": "tt6403442",
"tmdb": 1337377,
"tvrage": 0
},
"number_abs": 43,
"overview": "Kara deals with the loss of Mon-El by focusing all her energy on being Supergirl and the mysterious new threat against National City. Alex confesses a secret to Maggie about their impending nuptials. A citizen of National City has a mysterious connection to Kara, and Lena makes a bold move.",
"rating": 8.08503,
"votes": 294,
"first_aired": "2017-10-10T00:00:00.000Z",
"updated_at": "2017-10-10T12:09:22.000Z",
"available_translations": [
"bg",
"bs",
"cs",
"da",
"de",
"el",
"en",
"es",
"fa",
"fr",
"he",
"hu",
"id",
"it",
"ko",
"lt",
"nl",
"pl",
"pt",
"ro",
"ru",
"sv",
"th",
"tr",
"uk",
"zh"
],
"runtime": 45
}
bug Shows | Watched Backlog