The date and time the change was submitted, in the format YYYY-MM-DDThh:mm:ssZ, as specified in the ISO 8601 standard (for example, 2009-11-19T19:37:58Z). The Z after the time indicates that the time is listed in Coordinated Universal Time (UTC), which is synonymous with Greenwich Mean Time in this context.

public DateTime SubmittedAt { get; set; }