Php Tutorial strtotime () calculate the number of days between today and the specified date
$ Date1 = strtotime ('2017-04-30 '); // converts a date to a timestamp.
$ Date2 = time (); // Obtain the timestamp of the current time
$ Nowtime = strftime ("% y-% m-% d", $ date2); // format the output date
$ Days = round ($ date1-$ date2)/3600/24); // rounding
Echo "today is <font color =" red ">". $ nowtime. "</font> ";
Echo "<br/> distance ". strftime ("% y-% m-% d", $ date1 ). "and <font colr =" red "> ". $ days. "</font> day ";
Echo date ("y-m-d h: I: s", strtotime ("now"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("10 September 2000"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("+ 2 day"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("+ 1 week"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("+ 1 week 2 days 4 hours 2 seconds"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("next Thursday"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("last Monday"). "<br/> ";
Echo date ("y-m-d h: I: s", strtotime ("+ 3 day", strtotime ('2017-01-01 ')));