There are two period fields called Period and Period (order suggestion).
In the Period field you can enter the "to" (including) date for a planning horizon (up to which date you want to calculate requirements).
If you have selected Order suggestions under Show, you can use the Period (order suggestion) field to enter a "to" date as the planning horizon for the order suggestions that the system calculates.
Please note that the planning horizon for a date entered in the Period (order suggestion) field will be the same or tighter than a date entered in the Period field. The reason for this is that all order suggestions take the Safety time into consideration, as well as the Lead time for P-parts and Throughput time for M-parts and S-parts.