Read Google Fit automatically generated activities

Question

I'm struggling getting this to work as expected. I need to enumerate all the activities I see in Google Fit app (e.g auto "morning walk" or manual added running). I've used the following query:

DataReadRequest readRequest = new DataReadRequest.Builder()
    .aggregate(DataType.TYPE_ACTIVITY_SEGMENT, DataType.AGGREGATE_ACTIVITY_SUMMARY)
    .enableServerQueries()
    .setTimeRange(startTime, endTime, TimeUnit.MILLISECONDS)
    .bucketByTime(1, TimeUnit.DAYS)
    .build();

Note: this kind of aggregation is deprecated, but I cannot find the "right" way to receive the same result with the non-deprecated method.

Now: in my example day on Fit, I've two activities. The first is auto-generated "afternoon walk" of 2.32km and 32 min, the second is a manual added running activity of 1h. The query above returns two rows with fields activity/duration/num_segments:

1. Running / 3600000 (1h) / 1
2. Walking / 2674044 (~44mins) / 10

As you can see I get 12 minutes added for walking, why? How can I get the exact thing I see in the app? Moreover the total sum of steps for that day is not the sum of the two activities I see on Fit. What a mess...

EDIT: about timezone I'm getting it this way:

Calendar calendar = Calendar.getInstance(Locale.getDefault());
long endTime = calendar.getTimeInMillis();
calendar.add(Calendar.MONTH, -1);
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
long startTime = calendar.getTimeInMillis();

And these are the results for the specific day:

DATA TYPE: DataType{com.google.activity.summary[activity(i), duration(i), num_segments(i)]}

AS ACTIVITY: running FIELD: activity(i) START TIME: Fri Oct 16 12:10:00 GMT+02:00 2020 END TIME: Fri Oct 16 13:10:00 GMT+02:00 2020

---

DURATION: 3600000 FIELD: duration(i) START TIME: Fri Oct 16 12:10:00 GMT+02:00 2020 END TIME: Fri Oct 16 13:10:00 GMT+02:00 2020

---

N. SEGMENTS: 1 FIELD: num_segments(i) START TIME: Fri Oct 16 12:10:00 GMT+02:00 2020 END TIME: Fri Oct 16 13:10:00 GMT+02:00 2020

---

AS ACTIVITY: walking FIELD: activity(i) START TIME: Fri Oct 16 09:20:30 GMT+02:00 2020 END TIME: Fri Oct 16 23:15:17 GMT+02:00 2020

---

DURATION: 2674044 FIELD: duration(i) START TIME: Fri Oct 16 09:20:30 GMT+02:00 2020 END TIME: Fri Oct 16 23:15:17 GMT+02:00 2020

---

N. SEGMENTS: 10 2FIELD: num_segments(i) START TIME: Fri Oct 16 09:20:30 GMT+02:00 2020 END TIME: Fri Oct 16 23:15:17 GMT+02:00 2020