Q. What does the term "end of day" glass mean?

Harold Newman, in An Illustrated Dictionary of Glass (Thames & Hudson 1977), defines "end-of-day-glass" or "frigger" ("figgar") as:

A glass object, of various forms, made by a glassmaker in his own time and for his amusement and home decoration or for sale by him. They were usually made from the molten glass remaining in the pot [furnace] at the end of the day, considered as the workman's perquisite. In some regions [of England], they were made on Saturdays when the glasshouse was not working.... They...included such objects as jugs, candlesticks, ship models (nefs), animal figures, tobacco pipes, rolling pins, bells, hats, witch balls, musical instruments, and walking sticks. Such objects have been extensively copied in recent years. p. 125-126.

We also use the term "whimsies" for these types of objects. The Nailsea region of England is famous for its friggers made in the the late 18th and 19th centuries. I have attached a few bibliographies of resources on some different types of Friggers and Whimsies.