SSRS Report: Switch case

=switch(
Fields!BoxNumber.Value <=6, "Mon" & Fields!BoxNumber.Value,
Fields!BoxNumber.Value <=12, "Tue" & Fields!BoxNumber.Value mod 7 +1,
Fields!BoxNumber.Value <=18, "Wed" & Fields!BoxNumber.Value mod 13 +1,
Fields!BoxNumber.Value <=24, "Thu" & Fields!BoxNumber.Value mod 19 +1,
Fields!BoxNumber.Value <=30, "Fri" & Fields!BoxNumber.Value mod 25 +1
)