javascript - count down to multiple moments, how? -

i'm creating site neighbor has christmas light show.

the show runs every year 6 december till 1 january twice evening: @ 6.30pm , @ 8.00pm.

we want add countdown on website says:

next show: 00:00:00 (hh:mm:ss)

but how do that. when search on web every 1 says have use api countdown.

but use 1 date count down to, think have write 1 myself in javascript.

can that?

i guess have use many if/else statements, starting "is month 1, 12 or else?", followed "has yet been 18.30?" (i want 24-hours) , "has been 20.00" , on.

but there better way, because seems lot of work me.

javascript has built-in date object makes dealing dates , times bit less manual:

• mdn documentation javascript's date object

if supply no arguments constructor, it'll give current date (according end user's computer):

var = new date(); 

you can set specific date supplying year, month (zero-indexed january), day, , optionally hour, minute , second:

var = new date(); var first_show = new date(now.getfullyear(), 11, 6, 18, 30); 

you can use greater- , less-than comparisons on these date objects check whether date after or before another:

var = new date(); var first_show = new date(now.getfullyear(), 11, 6, 18, 30); alert(now < first_show);// alerts true (at date of writing) 

so, could:

1. create date objects current date, , each show year (and 1st jan shows next year)
2. loop through show dates in chronological order, and
3. use first 1 that's greater current date basis countdown.

note: should use server-side set now accurate parameters, instead of relying on new date(), because if end-user's computer set wrong time, it'll give wrong result.