help on cron expression

[vivien siu]

Hello,

I need help on writing a cron expression that will fire at 3 days before the last day of each month. Which means, if the last day is 31st, it will fire at 28th. And if the last day is 28th, it will fire at 25th.

the following does not work at all:
0 0 1 L-3 * *

[Jesper de Jong]

Did you try searching for "cron tutorial" with Google? This is what I found:

Newbie: Intro to cron
Cron Tutorial
Cron Tutorial. Cron, the linux event scheduler

etc.

[vivien siu]

I tried, but they are normally done using intervals, which I think in my case, is impossible

if I want to do the same thing, but trying to check whether current date is 3 days before the last day of month in Java, how can I do that?

[vivien siu]

btw... something is wrong with my browser and it's causing multiple threads here, can Admin please help me lock the extras up? Thanks!

[Jesper de Jong]

To find out if it is 3 days before the end of the month in Java, you could use the methods in java.util.Calendar.

Calendar c = Calendar.getInstance();
 
c.add(Calendar.MONTH, 1);
c.set(Calendar.DAY_OF_MONTH, 1);
c.add(Calendar.DATE, -4);
 
System.out.println("Three days before the end of the current month is: " + c.getTime());