Contract Line Level End Date to Auto-populate from Contract's Overview Tab

When a contract is created from an awarded negotiation and all the lines from the negotiation are also added to the contract created, we would like to know that when we key in the end date in the Contract's overview tab, can the same end date be defaulted to all the lines that are available in the contract's lines tab? Right now, it does not. Customer finds it a tedious process to key in end dates manually when there are more (> 30) lines available.