Your field is storing your "dates" as Text, since you are not including the
year. You'll need to store the "date" as:

05/01
05/02
05/03
etc.

Type in any year if you don't know the year of birth. Format the field so
that it only shows the month and year. I also added a tick field to indicate
that I didn't know the year of birth (that allowed me to calculate the age
of my aquaintances when I did know it).

Here is a function which you can paste into a module to calculate the date
of their next birthday: It ignores the year field so you can use it with a
dummy year and you can sort by this field.

Public Function NextBirthday(dtDate As Variant) As Date
Dim Been As Integer
Dim CurrentBirthday As Date

If Not IsNull(dtDate) Then
   CurrentBirthday = DateSerial(Year(Date), Month(varBirthdate),
Day(varBirthdate))
'Check when their birthday falls on this current year
   Been = Abs(CurrentBirthday(dtDate) < Date)
'if the birthday has already passed this year, then their next birthday is
next year.
   NextBirthday = DateSerial(Year(Date) + Been, Month(dtDate), Day(dtDate))
End If

End Function

You can then put into your query

DaysToBirthday: NextBirthday([DOB])-Date()

So you know how many days you have to save up for that mega present.

(DOB is the date of birth field which may contain the birthdate with a
random year)

Evi