SELECT Clients.[Code client], Clients.NOM, Clients.Prenom, Clients.DateNaissance, [Date commande]+[heure] AS Expr4, Hour(Now())<15 AS Expr1
FROM Clients INNER JOIN Commandes ON Clients.[Code client] = Commandes.[Code client]
GROUP BY Clients.[Code client], Clients.NOM, Clients.Prenom, Clients.DateNaissance, [Date commande]+[heure], Hour(Now())<15
HAVING ((([Date commande]+[heure])>=(Date()-1+(15/24)) And ([Date commande]+[heure])<=(Date()+(4/24))) AND ((Hour(Now())<15)=True)) OR ((([Date commande]+[heure])>=Date()+(15/24)) AND ((Hour(Now())<15)=False))
ORDER BY Clients.NOM, Clients.Prenom;