General News NASA: New Zodiac Sign and changing Dates

I Don't understand, so if there is a thirteenth sign and if it enters the cycle won't it change the dates and times of all the other signs? Like the new signtable in the article? So how is it that your sign won't be different if you aren't born on the day of the sign? Technically , according to current astrology there is not a single day for that sign is there ? Current astrology has completely ignored it and has given you dates according to a sun sign cycle where that sign isnt included.
Extending this thought, won't your moon sign also change?
The combination of sun and moon sign you know of is excluding the 13th sign, so won't both the cycles get altered with the signs entry. Clearly they have included the days of the 13th sign as that of some other sign all this while, so the error has always been there.
Further it's not like this is a new sign, it's a sign that has always existed , meaning to say it was there even in the year you were born in! So doesn't it mean that the zodiac cycle was wrong all throughout! So the signs on the day you were born could have been different?
And also like lazuri said, the change in axis didn't occur over one or two years, it's a gradual process, so the axis would have been different on the year you were born and hence the dates different.