Could consider mentioning that the index is already used, so that users will know that they need to add a task with a different index, as it could be a different task name but they chose a duplicated index. This could also be confusing for them if the index they chose to use for this week is a index that was used in the previous week.
Could consider mentioning that the index is already used, so that users will know that they need to add a task with a different index, as it could be a different task name but they chose a duplicated index. This could also be confusing for them if the index they chose to use for this week is a index that was used in the previous week.