iOS Development calculates a time interval of two dates

First create a formatted object

NSDateFormatter *dateformatter = [[NSDateFormatter alloc] init];

[Dateformatter setdateformat:@ "Yyyy-mm-dd HH:mm:ss"];

Then create a Date object

NSDate *date1 = [dateformatter datefromstring:@ "2020-10-31 00:00:00"];

NSDate *date = [NSDate Date];

Calculate time interval (units in seconds)

Nstimeinterval time = [Date1 timeintervalsincedate:date];

Calculate days, hours, minutes, seconds

int days = ((int) time)/(3600*24);

int hours = ((int) time)% (3600*24)/3600;

int minutes = ((int) time)% (3600*24)%3600/60;

int seconds = ((int) time)% (3600*24)%3600%60;

NSString *datecontent = [[NSString alloc] initwithformat:@ "Only%i days%i hours%i minutes%i seconds", days,hours,minutes,seconds];

(The%i can automatically convert the input to decimal, and%d does not convert)

Assign value Display

UILabel *timelab = (UILabel *) [Self.view viewwithtag:666666];

Timelab.text = datecontent;

iOS Development calculates a time interval of two dates