My neighbour is a professional gardener, and aside from his permanent job working on a large private estate, he also does some extra work for a garden contractor which contracts for mowing institutional lawns etc. Since 2020, he has persuaded the owners of one large area he mows regularly to let him do a first 'early' mow, then leave it until half-way through June. Of course it saves them money and it gives him extra free time at a period of the year when he needs it for his other interests. We're reasonably far north in England, and where he was mowing was on the edge of the pennines and at some elevation, so last frost can be fairly late - mid to end May.
Last year there was the reward of an entire bank of wild orchids flowering on a sloping bit of lawn which had been regularly mown every couple of weeks, apart from the winter months, for at least the past 20-plus years. The owners/managers asked him to care for that area appropriately so when he restarted mowing, he still left that area alone for a few more weeks and said he was very happy to see that in fine weather, staff would sit on the mown grass to eat their lunch, but were very careful about the area where the orchids were growing.
He is hoping for a bumper display this year. The landowners have put up notices about the area where the orchids grow so that it will be 'protected' for a long time.