Javascript Exercises - DateTime Practice

Datetime exercises

JavaScript date object is used to create dates and times. Date objects are based on a time value that is the number of milliseconds since 1 January, 1970 UTC.

Constructor :

new Date();
new Date(value);
new Date(dateString);
new Date(year, month[, day[, hour[, minute[, second[, millisecond]]]]]);

1. Write a JavaScript function to check whether an `input` is a date object or not.

Test Data :
console.log(is_date("October 13, 2014 11:13:00"));
console.log(is_date(new Date(86400000)));
console.log(is_date(new Date(99,5,24,11,33,30,0)));
console.log(is_date([1, 2, 4, 0]));
Output :
false
true
true
false

2. Write a JavaScript function to get the current date.

Note : Pass a separator as an argument.

Test Data :
console.log(curday('/'));
console.log(curday('-'));
Output :
"11/13/2014"
"11-13-2014"

3. Write a JavaScript function to get the number of days in a month.

Test Data :
console.log(getDaysInMonth(1, 2012));
console.log(getDaysInMonth(2, 2012));
console.log(getDaysInMonth(9, 2012));
console.log(getDaysInMonth(12, 2012));
Output :
31
29
30
31

4. Write a JavaScript function to get the month name from a particular date.

Test Data :
console.log(month_name(new Date("10/11/2009")));
console.log(month_name(new Date("11/13/2014")));
Output :
"October"
"November"

5. Write a JavaScript function to compare dates (i.e. greater than, less than or equal to).

Test Data :
console.log(compare_dates(new Date('11/14/2013 00:00'), new Date('11/14/2013 00:00')));
console.log(compare_dates(new Date('11/14/2013 00:01'), new Date('11/14/2013 00:00')));
console.log(compare_dates(new Date('11/14/2013 00:00'), new Date('11/14/2013 00:01')));
Output :
"Date1 = Date2"
"Date1 > Date2"
"Date2 > Date1"

6. Write a JavaScript function to add specified minutes to a Date object.

Test Data :
console.log(add_minutes(new Date(2014,10,2), 30).toString());
Output :
"Sun Nov 02 2014 00:30:00 GMT+0530 (India Standard Time)"

7. Write a JavaScript function to test whether a date is a weekend.

Note : Use standard Saturday/Sunday definition of a weekend.

Test Data :
console.log(is_weekend('Nov 15, 2014'));
console.log(is_weekend('Nov 16, 2014'));
console.log(is_weekend('Nov 17, 2014'));
Output :
"weekend"
"weekend"
undefined

8. Write a JavaScript function to get difference between two dates in days.

Test Data :
console.log(date_diff_indays('04/02/2014', '11/04/2014'));
console.log(date_diff_indays('12/02/2014', '11/04/2014'));
Output :
216
-28

9. Write a JavaScript function to get the last day of a month.

Test Data :
console.log(lastday(2014,0));
console.log(lastday(2014,1));
console.log(lastday(2014,11));
Output :
31
28
31

10. Write a JavaScript function to calculate 'yesterday day'.

Test Data :
console.log(yesterday('Nov 15, 2014'));
console.log(yesterday('Nov 16, 2015'));
console.log(yesterday('Nov 17, 2016'));
Output :
"Fri Nov 14 2014 00:00:00 GMT+0530 (India Standard Time)"
"Sun Nov 15 2015 00:00:00 GMT+0530 (India Standard Time)"
"Wed Nov 16 2016 00:00:00 GMT+0530 (India Standard Time)"

11. Write a JavaScript function to get the maximum date from an array of dates.

Test Data :
console.log(max_date(['2015/02/01', '2015/02/02', '2015/01/03']));
Output :
"2015/02/02"

12. Write a JavaScript function to get the minimum date from an array of dates.

Test Data :
console.log(min_date(['2015/02/01', '2015/02/02', '2015/01/03']));
Output :
"2015/01/03"

13. Write a JavaScript function that will return the number of minutes in hours and minutes.

Test Data :
console.log(timeConvert(200));
Output :
"200 minutes = 3 hour(s) and 20 minute(s)."

14. Write a JavaScript function to get the amount of days of a year.

Test Data :
console.log(days_of_a_year(2015));
365
console.log(days_of_a_year(2016));
366

15. Write a JavaScript function to get the quarter (1 to 4) of the year.

Test Data :
console.log(quarter_of_the_year(new Date(2015, 1, 21)));
2 console.log(quarter_of_the_year(new Date(2015, 10, 18)));
4

16. Write a JavaScript function to count the number of days passed since beginning of the year.

Test Data :
console.log(days_passed(new Date(2015, 0, 15)));
15
console.log(days_passed(new Date(2015, 11, 14)));
348

17. Write a JavaScript function to convert a Unix timestamp to time.

Test Data :
console.log(days_passed(new Date(2015, 0, 15)));
15
console.log(days_passed(new Date(2015, 11, 14)));
348

18. Write a JavaScript program to calculate age.

Test Data :
console.log(calculate_age(new Date(1982, 11, 4)));
32
console.log(calculate_age(new Date(1962, 1, 1)));
53

19. Write a JavaScript function to get the day of the month, 2 digits with leading zeros.

Test Data :
d= new Date(2015, 10, 1);
console.log(day_of_the_month(d));
"01"

20. Write a JavaScript function to get a textual representation of a day (three letters, Mon through Sun).

Test Data :
dt = new Date(2015, 10, 1);
console.log(short_Days(dt));
"Sun"

21. Write a JavaScript function to get a full textual representation of the day of the week (Sunday through Saturday).

Test Data :
dt = new Date(2015, 10, 1);
console.log(long_Days(dt));
"Sunday"

22. Write a JavaScript function to get ISO-8601 numeric representation of the day of the week (1 (for Monday) to 7 (for Sunday)).

Test Data :
dt = new Date(2015, 10, 1);
console.log(ISO_numeric_date(dt));
7

23. Write a JavaScript function to get English ordinal suffix for the day of the month, 2 characters (st, nd, rd or th.).

Test Data :
dt = new Date(2015, 10, 1);
console.log(english_ordinal_suffix(dt));
"1st"

24. Write a JavaScript function to get ISO-8601 week number of year, weeks starting on Monday.

Example : 42 (the 42nd week in the year)

Test Data :
dt = new Date(2015, 10, 1);
console.log(ISO8601_week_no(dt));
44

25. Write a JavaScript function to get a full textual representation of a month, such as January or June.

Test Data :
dt = new Date(2015, 10, 1);
console.log(full_month(dt));
"November"

26. Write a JavaScript function to get a numeric representation of a month, with leading zeros (01 through 12).

Test Data :
dt = new Date(2015, 10, 1);
console.log(numeric_month(dt));
"11"

27. Write a JavaScript function to get a short textual representation of a month, three letters (Jan through Dec).

Test Data :
dt = new Date(2015, 10, 1);
console.log(short_months(dt));
"Nov"

28. Write a JavaScript function to get a full numeric representation of a year (4 digits).

Test Data :
dt = new Date(2015, 10, 1);
console.log(full_year(dt));
2015

29. Write a JavaScript function to get a two digit representation of a year.

Examples : 79 or 04

Test Data :
dt = new Date(1989, 10, 1);
console.log(sort_year(dt));
"89"

30. Write a JavaScript function to get lowercase Ante meridiem and Post meridiem.

31. Write a JavaScript function to get uppercase Ante meridiem and Post meridiem.

32. Write a JavaScript function to swatch Internet time (000 through 999).

Test Data :
dt = new Date(1989, 10, 1);
console.log(internet_time(dt));
812

33. Write a JavaScript function to get 12-hour format of an hour with leading zeros.

Test Data :
dt = new Date(1989, 10, 1);
console.log(hours_with_zeroes(dt));
"12"

34. Write a JavaScript function to get 24-hour format of an hour without leading zeros.

Test Data :
dt = new Date(1989, 10, 1);
console.log(hours_without_zeroes(dt));
0

35. Write a JavaScript function to get minutes with leading zeros (00 to 59).

Test Data :
dt = new Date(1989, 10, 1);
console.log(minutes_with_leading_zeros(dt));
"00"

36. Write a JavaScript function to get seconds with leading zeros (00 through 59).

Test Data :
dt = new Date(1989, 10, 1);
console.log(seconds_with_leading_zeros(dt));
"00"

37. Write a JavaScript function to get Timezone.

Test Data :
dt = new Date();
console.log(seconds_with_leading_zeros(dt));
"India Standard Time"

38. Write a JavaScript function to find whether or not the date is in daylights savings time.

Test Data :
dt = new Date();
console.log(daylights_savings(dt));
1

39. Write a JavaScript function to get difference to Greenwich time (GMT) in hours.

Test Data :
dt = new Date();
console.log(diff_to_GMT(dt));
"+05.500"

40. Write a JavaScript function to get timezone offset in seconds.

Note : The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.
Test Data :
dt = new Date();
console.log(timezone_offset_in_seconds(dt));
19800

41. Write a JavaScript function to add specified years to a date.

Test Data :
dt = new Date(2014,10,2);
console.log(add_years(dt, 10).toString());
Output :
"Sat Nov 02 2024 00:00:00 GMT+0530 (India Standard Time)"

42. Write a JavaScript function to add specified weeks to a date.

Test Data :
dt = new Date(2014,10,2);
console.log(add_weeks(dt, 10).toString());
Output :
"Sun Jan 11 2015 00:00:00 GMT+0530 (India Standard Time)"

43. Write a JavaScript function to add specified months to a date.

Test Data :
dt = new Date(2014,10,2);
console.log(add_months(dt, 10).toString());
Output :
"Wed Sep 02 2015 00:00:00 GMT+0530 (India Standard Time)"

44. Write a JavaScript function to get time differences in minutes between two dates.

Test Data :
dt1 = new Date("October 13, 2014 11:11:00");
dt2 = new Date("October 13, 2014 11:13:00");
console.log(diff_minutes(dt1, dt2));
2

45. Write a JavaScript function to get time differences in hours between two dates.

Test Data :
dt1 = new Date("October 13, 2014 08:11:00");
dt2 = new Date("October 13, 2014 11:13:00");
console.log(diff_hours(dt1, dt2));
3

46. Write a JavaScript function to get time differences in days between two dates.

Test Data :
dt1 = new Date("October 13, 2014 08:11:00");
dt2 = new Date("October 19, 2014 11:13:00");
console.log(diff_days(dt1, dt2));
6

47. Write a JavaScript function to get time differences in weeks between two dates.

Test Data :
dt1 = new Date("June 13, 2014 08:11:00");
dt2 = new Date("October 19, 2014 11:13:00");
console.log(diff_weeks(dt1, dt2));
18

48. Write a JavaScript function to get time differences in months between two dates.

Test Data :
dt1 = new Date("June 13, 2014 08:11:00");
dt2 = new Date("October 19, 2014 11:13:00");
console.log(diff_months(dt1, dt2));
5

49. Write a JavaScript function to get time differences in years between two dates.

Test Data :
dt1 = new Date("June 13, 2014 08:11:00");
dt2 = new Date("October 19, 2017 11:13:00");
console.log(diff_years(dt1, dt2));
3