Android获取周/月起始时间：如何设置为00:00/23:59？

Hey there! Let's sort out that timestamp issue you're facing with fetching SHealth data. You've got the weekly and monthly start times mostly right, but the daily start/end isn't aligning to 00:00:00 and 23:59:59 UTC as you need. Here's how to fix it:

Key Issues in Current Implementation #

Looking at your existing code, the main gaps are:

• Not explicitly setting the UTC time zone (which SHealth typically uses for data timestamps)
• For the monthly start time, you weren't resetting the HOUR_OF_DAY field, so it kept the current hour instead of jumping to 00:00
• Missing dedicated functions for daily start/end times

Updated Functions for Daily, Weekly, and Monthly Timestamps #

1. Get Daily Start Time (00:00:00 UTC) #

This function resets all time fields to the start of the current UTC day:

public static long getStartTimeOfDay() {
    // Explicitly use UTC to match SHealth's timezone
    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);
    return cal.getTimeInMillis();
}

2. Get Daily End Time (23:59:59 UTC) #

To capture the final moment of the day, set all time fields to the end of the UTC day (we include milliseconds to avoid missing any last-second data):

public static long getEndTimeOfDay() {
    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    cal.set(Calendar.HOUR_OF_DAY, 23);
    cal.set(Calendar.MINUTE, 59);
    cal.set(Calendar.SECOND, 59);
    cal.set(Calendar.MILLISECOND, 999);
    return cal.getTimeInMillis();
}

3. Updated Weekly Start Time Function #

Your existing weekly function was close, but adding explicit UTC ensures consistency:

public static long getStartTimeOfWeek() {
    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);
    // Set to Sunday (DAY_OF_WEEK=1; adjust to 2 if you need Monday as week start)
    cal.set(Calendar.DAY_OF_WEEK, 1);
    return cal.getTimeInMillis() + ONE_DAY; // Adjustment for week start alignment
}

4. Updated Monthly Start Time Function #

Fix the missing HOUR_OF_DAY reset and add UTC to ensure it's truly the first moment of the month:

public static long getMonthDateFirstdate(){
    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
    cal.set(Calendar.HOUR_OF_DAY, 0);
    cal.set(Calendar.MINUTE, 0);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);
    cal.set(Calendar.DATE, cal.getActualMinimum(Calendar.DAY_OF_MONTH));
    return cal.getTimeInMillis();
}

Why This Works #

• Explicit UTC Timezone: Ensures your timestamps match the timezone SHealth uses for storing data, avoiding discrepancies from local timezone offsets
• Full Time Field Reset: Setting HOUR_OF_DAY, MINUTE, SECOND, and MILLISECOND to 0 (or max values for end time) guarantees you get the exact start/end of the period you need

内容的提问来源于stack exchange，提问作者Tanveerbyn