Before using SIL Script Custom Field, see Simple Issue Language documentation for a better grasp of SIL usage and capabilities.

The script is read-only. Please keep the following in mind:

• You must avoid changing any issue values in the script. In fact, you can change the issue variables but they will not be changed (issue will not be saved). However, routines may have side effects.
• This field only appears on the View screen of an issue or as a column in a JQL search

If you are not fully aware of what this implies, we recommend that you leave the option off.

interval age = currentDate() - created;
return "This issue is " + age + " old";

number noSubtasks = size(subtasks(key)); 
return "This issue has " + noSubtasks + " subtasks";

date now = currentDate(); // just to make sure we use the same reference date
string [] subtasks = subtasks(key);
interval age;
for(string task in subtasks){
 age = age + (now - %task%.created);
}
return "Average age of subtasks is " + (age / size(subtasks));

//select the city from the specified region
return sql("TestSQL", "select city from cities c, district d, region r where c.iddistrict=d.id and d.idregion=r.id and r.region='Bucharest'");

string field_name = "status";
string[] field_history = fieldHistory(key, field_name);
number n = arraySize(field_history);
date startDate; 
if (n > 0) {
 startDate = arrayGetElement(field_history, n - 2);
 return "Current issue has been " + status + " for " + (currentDate() - startDate);
}
return "Current issue has been " + status + " for " + (currentDate() - created);

string[] statuses;
string[] statusHistory = fieldHistory(key, "status");
for(number i = 1; i < size(statusHistory); i = i + 2) {
 string statusStr = getElement(statusHistory, i);
 statuses = addElementIfNotExist(statuses, statusStr);
}
return size(statuses);

string[] assignees;
assignees = addElementIfNotExist(assignees, userFullName(assignee)); 
string[] assigneeHistory = fieldHistory(key, "assignee"); 
for(number i = 1; i < size(assigneeHistory); i = i + 2) {
 string assigneeName = userFullName(getElement(assigneeHistory, i));
 assignees = addElementIfNotExist(assignees, assigneeName); 
}
return assignees;