date_sub
Do subtract days/hours/minutes/seconds from a particular date you may use the — operator and the TimeSpan object. E.g.:
${System.DateTime.Now - System.TimeSpan.FromDays(1)}
${System.DateTime.Now - System.TimeSpan.FromHours(1)}
${System.DateTime.Now - System.TimeSpan.FromMinutes(1)}
${System.DateTime.Now - System.TimeSpan.FromSeconds(1)}