Out here, in the summertime I won't schedule showings in the afternoon. It is too hot and I'm acclimated but they're usually not. Rare exception to this.
As I also advise clients that I'm a very early riser and dippy doodle after about 6 p.m., I don't like to show property after 4 or 5 p.m. at the latest no matter what the weather is. Rare exception.

Depends on the time of year - 5 during winter. Maybe 7 now.

It depends on the availability of the seller.

It depends upon the availability of the property and urgency of the showing.

I prefer not to do showings after 6. 

It depends. On the buyer. (And is it a first time viewing vs. a subsequent showing). The property.  Lots of different factors come into play.

1/2 hour before it gets dark. 

I won't show property 9pm or later. However, having said that, many times  sellers restrict the showing time anyway. 

Anytime

I typically schedule showings for during the late morning/early afternoon.  If I don't have that option (someone working during the week) I'll show a vacant home I have listed up until 7p (it gets dark around 8p here).

Depends on whether it is occupied, if vacant I authorize the showings at anytime their agent wants to show it.

It is extremely rare that I show any properties myself, generally I send others.

Our lockboxes stop working at 8:00pm, so I guess that is the latest.

there's no point in showing anything in the dark.... it must be shown again in the daylight before an offer is written....

It depends on how well I know said Buyer as well as many other circumstances Dan Capra . Some days, some Buyers 4:30 PM. Other days other buyers 9:00 PM

Dan,

In commercial real estate, one rarely shows property after business hours.  If I were in residential, I would be in the luxury end or the spectrum, and I would not show after dark.  A

Good answers are here. I hope you find the best one. 

Great question and asnwers. Good luck. 

9:30 p.m.

7pm lockboxes stop working after that!

It depends... on the buyer, on my schedule, whether the seller allows it, whether it's already dark outside, whether it's a weekend. Too many variables. In general, I tell my clients up-front I don't work past 7pm, but if they want to be out with me at 7am I am happy to accommodate them.

8ish and it depends whether it is a vacant propety. Each deal is different.

No set time but likely not after it gets dark

8:30pm

For vacant properties 7 P.M. for properties that are occupied 5 P.M. I understand that people get off work at different times but I loathe having to have a family or person vacate their home for an hour after a long day of work. Vacant not an issue but I do like time with my family so 7 P.M is my cut off. 

Sunday

8PM, depending on the home - if it's a hot house and HAS to be toured in the evening.

Just before dusk so they can see the outside!

If this is the sale then do what it takes. 

I've been out as late (early) as 1am. It's so, so subjective although if they're willing so am I.

Summertime nothing after 8:30 pm ....winter 5:00 pm otherwise too dark, only will to do second showing if they have seen the whole property on the 1st showing

I have shown in the dark, but prefer to stay in daylight hours.  Easier to see the home, and surrounding area.

That would depend on the Seller as to what time is convenien to them.  I will show properties up to 9:00 p.m. but no later than that.

During daylight

Depends

Dan Capra - the answer is perhaps the same: What are your sellers comfortable with?

And if you have electronic supra lock, I think it is up to 8 PM.

As late as the sellers will allow it to be shown. I hate showing in the fall/winter when it gets dark so early. I like to be able to see the exterior and the views from the home when I show. 

As late as the lockbox will allow me to access.

I will show up until dark with the seller's permission.

Depending on the time of year, but as long as it is somewhat light