We have Chinese citizen friends that plan to departure from Beijing and change flight in Amsterdam (connection time over 24 hours, almost 36). The final destiny is Cape Verde, but the connection flight in Amsterdam is to Casablanca (Air Maroc).
Is this OK?
A Timatic search using the Emirates site says:
Transit - Netherlands (NL) Visa required. Visa Exemptions: Passengers with a Hong Kong (SAR China) passport for a maximum stay of 90 days. Passengers with a Macao (SAR China) passport for a maximum stay of 90 days. TWOV (Transit Without Visa): Holders of onward tickets transiting by the same or first connecting aircraft:
So if you booked the flights to and from Amsterdam together, this is a connection, and no visa is required, despite the long connection time. But if they're separate flights (and the long connection time hints that it might be so), visa is required.