Most tradesmen have their numbers switched to their mobiles so ringing during the day is best. If it's someone I know I will send a text on an evening then they have the choice to respond the same day or next.
I'm a ditherer too. I would rather email than phone but unless they have office staff I wonder how long it would take to pick them up. I phone in the morning if I need a plumber, electrician etc. I leave a message if they don't answer.
I ring during the day because many switch off their phones evenings and weekends if they are not on 24/7 call. If I end up leaving a message a decent tradesman will ring back. I also do not like to disturb their leisure time.
This may be a silly question but I always worry about what time to call a trades-man-person. If I have a card with their mobile number, I think that if I call them during the day I'll be stopping them working but if I ring them in the evening or at weekends I'll be disturbing their time with their family ( or in the pub). I'm probably overthinking it but I get nervous making phone calls anyway and I dither about choosing the right time to make the call. Any advice please.