ONLY GOD IS HOLY, just as only people are human. God's holiness is God's Godness. To speak of anything else as holy is to say that it has something of God's mark upon it. Times, places, things, and people can all be holy, and when they are, they are usually not hard to recognize.
One holy place I know is a workshop attached to a barn. There is a wood-burning stove in it made out of an oil drum. There is a workbench, dark and dented, with shallow, crammed drawers behind one of which a cat lives. There is a calendar on the wall, plus various lengths of chain and rope, shovels and rakes of different sizes and shapes, some worn-out jackets and caps on pegs, an electric clock that doesn't keep time. On the workbench are two small plug-in radios, both of which have serious things wrong with them. There are several metal boxes full of wrenches and a bench saw. There are a couple of chairs with rungs missing. There is an old yellow bulldozer with its tracks caked with mud parked against one wall. The place smells mainly of engine oil and smoke—both wood smoke and pipe smoke. The windows are small, and even on bright days what light there is comes through mainly in window-sized patches on the floor.
I have no idea why this place is holy, but you can tell it is the moment you set foot in it if you have an eye for that kind of thing. For reasons known only to God, it is one of the places God uses for sending God's love to the world through.