Dimanche prochain
On Sunday is "le dimanche" in French.
you can say OPEN SUNDAY : ouvert le dimanche
'I was born on a Sunday' is tranlated 'je suis né un dimanche' in French.
dimanche dernier
Dimanche gras.
arrivé dimanche
Aujourd'hui, c'est dimanche.
To say "next March" in French, you can say "le mois de mars prochain" or "mars prochain."
You would say "samedi prochain" in French to refer to next Saturday.
Next Saturday is the 24th of June. We would also say that "This Sunday" is the 25th of June, though we might use "This Sunday coming" or "Next Sunday". Context can be importance in terms of what words we use.
dimanche dernier je / j'ai
dimanche après-midi