import calendar


def get_month_button(month, text=None):
    """
    Get the button corresponding to the given month.

    If no `text` is given, the name of the month in English will be used.
    """
    if month < 1:
        month += 12
    elif month > 12:
        month -= 12

    return {
        'text': text or calendar.month_name[month],
        'callback_data': f'birthday/add/m{month:02}'
    }