Get current time of day in seconds

Question

Is there a way to get the current time of the day in seconds? Notice I am asking the time of the day, not UTC time.

What I want is a value (in seconds) between the range 0 - 86,400 (12:00AM - 11:59PM). I'm working on an app that works on a daily basis, and when the day ends, the time (in seconds) should restart back at 0 again.

So let's say it's 10:00AM. I should be getting 36,000 seconds, and if my time is 5:00PM, I should be getting 61,200 seconds.

PS: I do not know the time before hand. The program will figure it out by itself using a currentTime() function.

Answer 1

With Java 8, you could create a Duration instance.
For example :

LocalDateTime date = LocalDateTime.now();
long seconds = Duration.between(date.withSecond(0).withMinute(0).withHour(0), date).getSeconds();

Or more simply you could convert the LocalDateTime to a LocalTime instance and then apply the toSecondOfDay() method :

LocalDateTime date = LocalDateTime.now();
int seconds = date.toLocalTime().toSecondOfDay();

From the java.time.LocalTime javadoc :

public int toSecondOfDay()

Extracts the time as seconds of day, from 0 to 24 * 60 * 60 - 1.

Answer 2

Use a java.time.LocalTime and a java.time.temporal.ChronoField:

// 10:00 AM
LocalTime d = LocalTime.of(10, 0);
System.out.println(d.get(ChronoField.SECOND_OF_DAY)); // 36000

// 05:00 PM
d = LocalTime.of(17, 0);
System.out.println(d.get(ChronoField.SECOND_OF_DAY)); // 61200

// 23:59:59
d = LocalTime.of(23, 59, 59);
System.out.println(d.get(ChronoField.SECOND_OF_DAY)); // 86399

// midnight
d = LocalTime.of(0, 0);
System.out.println(d.get(ChronoField.SECOND_OF_DAY)); // 0

This prints:

36000
61200
86399
0

---

Notes:

• That's just examples. If you want to get the value from the current time, just use LocalTime.now() (or LocalTime.now(ZoneId.of("timezone-name")) as pointed by @Ole V.V.'s answer).

  As a timezone-name, always use IANA timezones names (always in the format Continent/City, like America/Sao_Paulo or Europe/Berlin). Avoid using the 3-letter abbreviations (like CST or PST) because they are ambiguous and not standard. You can get a list of available timezones (and choose the one that fits best your system) by calling ZoneId.getAvailableZoneIds().

• You can also call d.toSecondOfDay() if you want (it's equivalent, as get(ChronoField) internally calls toSecondOfDay).

Answer 3

I suggest:

    int secondsOfDay = LocalTime.now(ZoneId.of("Europe/Rome")).toSecondOfDay();

Points to note:

• Use an explicit time zone to remind the reader and yourself that the choice of time zone matters and that you have made a conscious choice. Either ZoneId.systemDefault(), or even better is if it would make sense in your situation to give a named zone like for example ZoneId.of("Europe/Rome").
• The snippet converts 10:00 AM to 36,000 no matter when the day began; because of summer time and other anomalies it may not have begun at 0:00 midnight, and there may be a gap or overlap early in the morning. To get the true number of seconds since the day began, you will need some calculation involving LocalDate.now(yourTimeZone).atStartOfDay(yourTimeZone).

Answer 4

You can just convert the seconds minutes hour fields into seconds and add them up

Calendar c = new GregorianCalendar();
int totalSecs = c.get(Calendar.SECOND) + 60 * c.get(Calendar.MINUTE) + 3600 * c.get(Calendar.HOUR_OF_DAY);

Answer 5

You could use the SimpleDateFormat to extract the hours minutes and seconds. It works on Java 7 and Java 6 and Java 8, and it adapts to your local time and timezone:

String timeNowHMS[] = new SimpleDateFormat("HH:mm:ss", Locale.ENGLISH)
        .format(System.currentTimeMillis())
        .split(":");

int secondsPassedInTheDay =
    Integer.parseInt(timeNowHMS[0]) * 60 * 60
        + Integer.parseInt(timeNowHMS[1]) * 60
        + Integer.parseInt(timeNowHMS[2]);