Need to get date-time in seconds from current date.
Want to add 2 days from current date-time and get value of 7 PM of result day.
I.E.
Current date-time is 1 January, 7:05 PM OR 6:55 PM, I should get value of 3 January, 7:00 PM in seconds.
P.S. - Can't use JODA Time & Java 8.
Did you try ThreeTenABP by Jake Wharton? https://github.com/JakeWharton/ThreeTenABP. You can use it also for android versions before api 26 (required for the new java.time.instant) and it has all the functionalities of the Java 8 api.
I would do:
LocalDate myDate;
myDate = LocalDate.now().plus(2, ChronoUnit.DAYS);
LocalDateTime myDateAtTime = myDate.atTime(19,0,0);
long millis = myDateAtTime.toEpochSecond(ZoneOffset.UTC);
Without using Java 8 you can do something like this:
public static void main(String[] args) throws Throwable {
Calendar c = Calendar.getInstance();
c.add(Calendar.DAY_OF_YEAR, 2);
c.set(Calendar.HOUR_OF_DAY, 19);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
System.out.println(c.getTimeInMillis() / 1000L); // Time in seconds in two days at 7:00 pm
}
You could also create a static method for this:
private static long timeInTwoDaysAt7pm() {
Calendar c = Calendar.getInstance();
c.add(Calendar.DAY_OF_YEAR, 2);
c.set(Calendar.HOUR_OF_DAY, 19);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
return c.getTimeInMillis() / 1000L;
}
If java 8 is a no go, then you can use Calendar :
import java.util.Calendar
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DAY_OF_YEAR, 2);
calendar.set(Calendar.HOUR_OF_DAY, 19);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
Not sure if this is a correct approach or any better solution is there.
Date dt = new Date();
Calendar c = Calendar.getInstance();
c.setTime(dt);
c.add(Calendar.DATE, 2);
c.set(Calendar.HOUR_OF_DAY, 19);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
long timeInSeconds = c.getTime().getTime() / 100;
Related
I have variable with value of timeInMills which is past 3 days ago, I wanted to reset the date of it to current date but the time should be still.
Calendar calNow = Calendar.getInstance();
Calendar calSets = (Calendar)calNow.clone();
calSets.setTimeInMillis(TIME_IN_MILL); //set datetime from timeInMillis
//Reset the date to current Date.
How to do that?
Like this, get the properties you want, before you change the instance:
Calendar calNow = Calendar.getInstance();
Calendar calSets = (Calendar)calNow.clone();
int hours = calNow.get(Calendar.HOUR_OF_DAY)
int minutes = calNow.get(Calendar.MINUTE)
calSets.setTimeInMillis(TIME_IN_MILL); //set datetime from timeInMillis
//Reset the date to current Date.
calSets.set(Calendar.SECOND, 0);
calSets.set(Calendar.MILLISECOND, 0);
calSets.set(Calendar.HOUR_OF_DAY, hours);
calSets.set(Calendar.MINUTE, minutes);
You can reset a Calendar by calling setTimeInMillis(System.currentTimeMillis()):
TimeZone.setDefault(TimeZone.getTimeZone("UTC")); // Just for testing
final long TIME_IN_MILL = 1563204600000L; // 2019-07-15 15:30 UTC
Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(TIME_IN_MILL);
int hour = cal.get(Calendar.HOUR_OF_DAY);
int minute = cal.get(Calendar.MINUTE);
cal.setTimeInMillis(System.currentTimeMillis()); // Reset
cal.set(Calendar.HOUR_OF_DAY, hour);
cal.set(Calendar.MINUTE, minute);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(cal.getTime()));
The code prints 2019-07-18 15:30:00.000, which is todays date with the time of day from the TIME_IN_MILL value.
If you don't want to rely on System.currentTimeMillis(), just get the value from the Calendar object, first thing:
Calendar cal = Calendar.getInstance();
long now = cal.getTimeInMillis();
cal.setTimeInMillis(TIME_IN_MILL);
int hour = cal.get(Calendar.HOUR_OF_DAY);
int minute = cal.get(Calendar.MINUTE);
cal.setTimeInMillis(now);
cal.set(Calendar.HOUR_OF_DAY, hour);
cal.set(Calendar.MINUTE, minute);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
Is there an existing android or java or joda-time function for converting minutes since midnight to time? I know how to do it for a 24 hour period without the am/pm bit. But I need to have the am/pm for some users.
This is for an android app. So the added benefit of using a standard function is that it will conform to the general preference of the user.
I suppose I can roll out my (buggy) own if such does not exist.
You could use Calendar and SimpleDateFormat to get that. Something like,
static DateFormat _sdf = new SimpleDateFormat("hh:mm a");
static String minutesSinceMidnight(int minutes) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.AM_PM, Calendar.AM);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
cal.add(Calendar.MINUTE, minutes);
return _sdf.format(cal.getTime());
}
I have a config file from where I am reading a day of week and a time of day in 24 hour format. A sample entry looks like this:
NextRun=Sunday|15:00:00
I will parse them out into day and time variables. However, I want to find the equivalent millisecond timestamp for the next Sunday 3:00pm.
So for example, if today is Sunday 4:00pm or Tuesday 1:00am it will be the next Sunday 3:00pm, but if it is Sunday 2:30pm now, the expected time will be 30 minutes from now.
Get a Calendar instance and set it with the parsed time and day. If it has passed, add a week.
Calendar c = Calendar.getInstance();
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
c.set(Calendar.HOUR_OF_DAY, 15);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
if (c.getTimeInMillis() - Calendar.getInstance().getTimeInMillis() < 0)
c.add(Calendar.DAY_OF_YEAR, 7);
return c.getTimeInMillis();
Use GregorianCalendar which extends Calendar. try something like:
GregorianCalendar currentTime = new GregorianCalendar();
GregorianCalendar targetTime = new GregorianCalendar();
//Get Day and Time from config file
targetTime.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
//Add a week if the targetTime is from last Sunday
if (targetTime.before(currentTime))
{
targetTime.add(Calendar.DAY_OF_YEAR, 7);
}
System.out.println(currentTime.getTime().toString() + ", " + targetTime.getTime().toString());
I want to calculate time difference in milliseconds from current time of a day(11 am , 1 october,2012) and time at midnight for the same day (11 pm 59 m 59s , 1 october , 2012.
I have tried this
Calendar cal = Calendar.getInstance();
cal.add(Calendar.SECOND, 59);
cal.add(Calendar.HOUR, 23);
cal.add(Calendar.MINUTE, 59);
cal.getTime().getTime() - today.getTime();
here today is the current date.
But when i print long values of cal and today , the time difference if of 86400 approx one day.
Use cal.set() instead of cal.add()
Calendar cal = Calendar.getInstance();
cal.set(Calendar.SECOND, 59);
cal.set(Calendar.HOUR, 23);
cal.set(Calendar.MINUTE, 59);
long diff = cal.getTime().getTime() - today.getTime();
You can set your date to newly created Calendar instance..
And then compare it with current instance using getTimeInMillis()
Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR, 23);
cal.set(Calendar.MINUTE, 59);
cal.set(Calendar.SECOND, 59);
cal.set(Calendar.DATE, 1);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.YEAR, 2012);
long difference = cal.getTimeInMillis() - Calendar.getInstance().getTimeInMillis();
May be like this:
for(int i=0;i<15;i++){
Calendar cal = new GregorianCalendar();
cal.add(Calendar.DAY_OF_MONTH, -1);
if (cal.Calendar.DAY_OF_WEEK==1){
System.out.println(cal.cal.getTime())
But may be exists more simple way?
Thanks.
You are on the right track.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_YEAR, -7); // First week before
cal.add(Calendar.DAY_OF_YEAR, -7); // Second week before
Let me make this work for just Mondays.
Calendar cal = Calendar.getInstance();
int weekday = cal.get(Calendar.DAY_OF_WEEK);
int days = (Calendar.SATURDAY - weekday + 2) % 7;
cal.add(Calendar.DAY_OF_YEAR, days);
cal.add(Calendar.DAY_OF_MONTH, -7);
cal.add(Calendar.DAY_OF_MONTH, -7);
Even simpler would be to set the weekday directly:
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
cal.add(Calendar.DATE, -7);
System.out.println(cal.getTime());
Please keep in mind, that this does not effect the time. If you want 00:00, you need to set the appropriate values:
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
java.time
Use a TemporalAdjuster.
LocalDate today = LocalDate.now();
LocalDate previousOrSameMonday = today.with( TemporalAdjusters.previousOrSame( DayOfWeek.MONDAY ) );
And subtract a week to get a second one.
LocalDate secondMondayBefore = previousOrSameMonday.minusWeeks( 1 );