Whether the travel date can be modified without a reservation after purchase usually depends on the specific policy of the ticket purchasing platform or the service provided. Here are some general steps:

  1. Check the policy of the ticket purchasing platform: Log in to the ticket purchasing platform and check its regulations on ticket changes or refunds.
  2. Contact customer service: If the platform policy is unclear, you can try to contact customer service for consultation.
  3. Prepare in advance: Prepare the ID information used when purchasing tickets so that customer service can help process it.
  4. Change or refund tickets: Change or refund tickets according to the guidance of customer service.

Please note that different platforms and different types of tickets (e.g. train tickets, plane tickets, etc.) may be processed differently. It is recommended to read the relevant policies carefully before operating.