şabat

/ ʃabat /

Cases

SingularPluralWhen to use it
nominative şabat the Saturday şabatla the Saturdays the plain dictionary form — the doer of the sentence
genitive şabatnı the Saturday's şabatlanı the Saturdays' the owner — whose it is
accusative şabatnı the Saturday (as the object) şabatlanı the Saturdays (as the object) a specific, known object — whom or what
dative şabatha to the Saturday şabatlağa to the Saturdays direction or recipient — to where, to whom
locative şabatda at / in the Saturday şabatlada at / in the Saturdays where it is; also having — mende bar, "I have it"
ablative şabatdan from the Saturday şabatladan from the Saturdays where it comes from; also "than" when comparing

The endings are the same ones the pronouns wear — that page explains when each case is used.

With an owner

One ownedSeveral owned
my şabatım my Saturday şabatlarım my Saturdays
your şabatıŋ your Saturday şabatlarıŋ your Saturdays
his / her şabatı his / her Saturday şabatları his / her Saturdays
our şabatıbız our Saturday şabatlarıbız our Saturdays
you all's şabatığız you all's Saturday şabatlarığız you all's Saturdays
their şabatları their Saturday şabatları their Saturdays

The overlap in the last rows is real, not a mistake: şabatları can mean "his / her Saturdays", "their Saturday", or "their Saturdays" — context decides.