function readOnly(count){ }
Sign Up ›
Starting November 20, the site will be set to read-only. On December 4, 2023,
forum discussions will move to the Trailblazer Community.
Learn More

Browse by Topic
ShowAll Questionssorted byDate Posted
+ Start a Discussion
AsaktiAsakti 

what does the below expression mean

ScheduleCreateTargetBatch schedule =new ScheduleCreateTargetBatch();

String sch ='0 0 0 1 4 ?';
;
String sch1 ='0 0 2 1 JAN,APR,JUL,OCT ?';
 
Suraj Tripathi 47Suraj Tripathi 47

Hi,

Please find the solution.

String sch ='0 0 0 1 4 ?';
0     0     0     1      4      ?

1     2     3     4      5      6

{1} Seconds - so 0 here i.e. start of the minute.
{2} Minutes - 0 again so start of the hour.
{3} Hours -  0 so 12 am. Uses 24 hour notation so 21 = 9pm
{4} Day_of_month - 1
{5} Month -  April
{6} Day_of_week - ? means no specific value, only available for  week.
String sch1 ='0 0 2 1 JAN,APR,JUL,OCT ?';
0     0     2     1      JAN,APR,JUL,OCT            ?

1     2     3     4                    5                         6

{1} Seconds - so 0 here i.e. start of the minute.
{2} Minutes - 0 again so start of the hour.
{3} Hours -  2 so 2 am. Uses 24 hour notation so 21 = 9pm
{4} Day_of_month - 1
{5} Month -  April    -JAN,APR,JUL,OCT
{6} Day_of_week - ? means no specific value, only available for  week.

Please mark it as the Best Answer If it helps you.

Thank You
AbhinavAbhinav (Salesforce Developers) 
Hi, 
 
These expressions  are Cron Expression. 

As we all know that Salesforce provides us with a very great feature of Scheduling an apex class. In a standard way through customization part, we can schedule an apex class with the frequency of weekly days or monthly dates with a preferred start time. But through CRON expression we can schedule an apex with our customized date time or occurrence through code. That’s an interesting feature that salesforce allows developers to customize according to their own need and scenario.

You can get detail about cron expression from below link:

https://www.forcetalks.com/blog/using-cron-expression-in-salesforce/

Thanks!
mukesh guptamukesh gupta
Hi Askit,

According your cron:-

String sch ='0 0 0 1 4 ?';   this will execute 1 april every year

Cron Expression Examples 
ExpressionDescription0 0 0 ? * * *at 12:00 AM every day
0 0 10 ? * *at 10.00 AM every day
0 0 10 * * ?at 10.00 AM every day
0 0 10 * * ? *at 10.00 AM every day
0 0 15 ? * * *at 3:00 PM every day
0 0-5 15 * * ?Every minute starting at 3:00 PM and ending at 3:05 PM, every day
0 15 17 ? * MON-FRIat 5:15 PM every Monday, Tuesday, Wednesday, Thursday and Friday
0 15 10 15 * ?at 5:15 PM on the 15th day of every month
0 15 17 ? * 6#3at 5:15 PM on the third Friday of every month
0 0 18 ? * 6Lruns the last Friday of every month at 6:00 PM.
‘0 30 * * * *’;every 30 minutes
0 0 12 * * ?at 12:00 PM every day
0 0 23 * * ? 2016runs every day at 11:00 PM during the year 2016.

if you need any assistanse, Please let me know!!

Kindly mark my solution as the best answer if it helps you.

Thanks
Mukesh