テンプレート:User current age/months

{{#ifexpr:09-{{{month}}}<0

|{{#expr:12-(21<{{{day}}})+09-{{{month}}}}}
|{{#ifexpr:{{{day}}}<=21
 |{{#expr:09-{{{month}}}}}
 |{{#ifexpr:09-{{{month}}}-1<0
  |{{#ifexpr:09={{{month}}}
   |11
   |0
  }}
  |{{#expr:09-{{{month}}}-1}}
 }}
}}

}}