Need to change the Language in the Error message appear while submitting the Timecard by the user

Summary: When we change the Transaction start date for any Task of any project which is starting from future date ,this task takes very long time to get updated and to be vanished away in the current time card screen (Redwood View) and user still able to see that task under the "Task name" field while selecting the project with which the task is associated. During that time If user is selecting that Task The user is not able to submit the Timecard, which is correct but the error message which gets displayed is not clear. For better understanding of users,