Why do you want to define day types ?
To define day types follow below path :
Time Management ---> Work Schedules --> Day Types --> Define Day Types.(V_T553T)
If you are using them while defining a rule then you need to attach them with your Work Scedule rule in view V_T508A.
Suppose you want to define specific day as part of your DWS then you can use this as follows:
You have a scenario that every alternate saturday it should be off:
Define a day type (V_T553T) (for e.g. 4 Off/Al Saturday )
Define a rule (T553A) ( For. e.g.: 04 1 1111111 1 1111111 1111111111)
Attach the day type and rule with that particular day (for e.g. 04 10.09.2011 4 Off/Al Saturday)
Now attach this rule with your work schedule (V_T508A) in field MOTTY as "04" (Rule name)
The day type determines payment as well as planned absences and attendances for a specific calendar day in the work schedule. The day type is necessary for absence counting and for wage type selection.
The standard system contains four day types:
blank: Day on which an employee works and is paid
1: Day on which an employee does not work, but is still paid
2: Day on which an employee does not work and is also not paid
3: Special day on which an employee does not work and is paid according to payroll rules
In the work schedule, the day type determines whether employees must work on a specific day and whether or not they are paid.
Day types are assigned to the individual calendar days using selection rules for day types.
The day type is determined by the day of the week (workday, Saturday, Sunday) and by the public holiday class for that day of the week.
The selection rules are indicated by a number (rule). The work schedule rule specifies which rule is used to determine the day type.
Special days are days that are not public holidays but are handled differently. Such special days include "bridge days" immediately before or after a public holiday, that is, days on which a group of employees might be off work.
Special days are indicated by day type 3 in the standard system. A special day is defined by a specific date; the applicable day type for special days is assigned directly, regardless of the day of the week or public holiday class.
This date is assigned to a selection rule for day types. One or more special days can be defined for each selection rule.
The selection rule for day types (including the specification of special days) is assigned to the work schedule rule.
You determine the payment for special days in Payroll.