I've been contacted by a property deveoper who wants a timelapse from sunrise to sunset tomorrow. I've done many holygrail timelapse but only for sunrise or for sunset, never for such a long period of time.

I shoot with the 5d mark 3 and magic lantern. I normally shoot my holygrail video with an interval of 6-7 seconds. But here we would be looking at  
Probably 30s second interval?
 
Would you stay on location the whole time to adjust the shutter speed as I’d do with a normal sunrise photo?

Any advice would be appreciated!

Thanks

I'd use shorter intervals. Say 10 secs, otherwise the intersting transitions would be too fast. During the day everything will be boring anyway, so you can speed this up later in post.
Otherwise do the ramping in the morning and in the evening. During the day you can leave the camera alone.

I'd use shorter intervals. Say 10 secs, otherwise the intersting transitions would be too fast. During the day everything will be boring anyway, so you can speed this up later in post.
Otherwise do the ramping in the morning and in the evening. During the day you can leave the camera alone.

Great advice, thanks gunther. i was worried about the battery running out in the middle of the day!

Sure, you should use an external power source, like a powerbank to power the camera.

Ha! I need to buy one!