${SQL:SELECT DATEDIFF(mi, '${AlertTriggerTime}', GETDATE())/60 } : ${SQL:SELECT DATEDIFF(mi, '${AlertTriggerTime}', GETDATE())%60 }
To learn more, see arithmetic operators in SQL - Arithmetic Operators (Transact-SQL)
${SQL:SELECT DATEDIFF(mi, '${AlertTriggerTime}', GETDATE())/60 } : ${SQL:SELECT DATEDIFF(mi, '${AlertTriggerTime}', GETDATE())%60 }
To learn more, see arithmetic operators in SQL - Arithmetic Operators (Transact-SQL)