Its that time of year when we regularly get asked "do we scrape same or next day?"
In all honesty its a tough question as all render have slightly differing setting attributes. I understand the eagerness to move to same day scrapes but its not something that can be rushed. Trying to scrape off a wet, sticky render will throw off the colour and create nasty texturing issues which are difficult to resolve.
As a general rule if the air is dry and temps are predicted to be in the double figures from the minute you start until the end of the day then your render should be good to scratch the same day, but expect maybe a late finish if the temps are at the lower end of that scale. Get the pumps and trowel working early too!