Andrew If Revolut is able to send an Instant SEPA transfer (different system than the regular SEPA transfer), then indeed you will get the money in less than 10 seconds, regardless of weekends/holidays etc.
A regular SEPA transfer can take a bit longer and is never executed on weekends and certain holidays. But today (Friday 31st) you still have a good chance even if you send it via regular SEPA transfer because it's a normal business day. I would expect the money to arrive after 3-4 hours, but only if you send it early in the day (try to send it as early as possible, but definitely no later than ~1pm. I'm not sure about Revolut processing times, so better be safe than sorry). There's no guarantee for it to arrive that early, though, that's why bunq will always say 1-2 business days.