Does room temperature glass deform to fit the shape of its container? That is the definition I remember from 7th grade, and it doesn’t seem to qualify glass as a liquid at room temperature and pressure.

According to Wikipedia, the glass transition temperature for soda lime glass is 573 °C (1,063 °F) . This is the point where it goes from its glassy, amorphous solid state to the rubbery, viscous liquid state. https://en.wikipedia.org/wiki/Glass_transition

From Wikipedia:

The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle “glassy” state into a viscous or “rubbery” state as the temperature is increased.^[2] An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification.

Two-dimensional, schematic, representation of the lattices of quartz (a), silica (b), and of silica based glasses ©.^[1]

The glass-transition temperature T_g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, T_m, of the crystalline state of the material, if one exists, because the glass is a higher energy state (or enthalpy at constant pressure) than the corresponding crystal.

[…]

Despite the change in the physical properties of a material through its glass transition, the transition is not considered a phase transition; rather it is a phenomenon extending over a range of temperature and defined by one of several conventions.^[4][5] Such conventions include a constant cooling rate (20 kelvins per minute (36 °F/min))^[2] and a viscosity threshold of 10¹² Pa·s, among others. Upon cooling or heating through this glass-transition range, the material also exhibits a smooth step in the thermal-expansion coefficient and in the specific heat, with the location of these effects again being dependent on the history of the material.^[6] The question of whether some phase transition underlies the glass transition is a matter of ongoing research.^[4][5][7]^[when?]^

[…]

Thus, the liquid-glass transition is not a transition between states of thermodynamic equilibrium. It is widely believed that the true equilibrium state is always crystalline. Glass is believed to exist in a kinetically locked state, and its entropy, density, and so on, depend on the thermal history. Therefore, the glass transition is primarily a dynamic phenomenon. Time and temperature are interchangeable quantities (to some extent) when dealing with glasses, a fact often expressed in the time–temperature superposition principle. On cooling a liquid, internal degrees of freedom successively fall out of equilibrium. However, there is a longstanding debate whether there is an underlying second-order phase transition in the hypothetical limit of infinitely long relaxation times.^[clarification needed][6][18][19][20]^

In a more recent model of glass transition, the glass transition temperature corresponds to the temperature at which the largest openings between the vibrating elements in the liquid matrix become smaller than the smallest cross-sections of the elements or parts of them when the temperature is decreasing. As a result of the fluctuating input of thermal energy into the liquid matrix, the harmonics of the oscillations are constantly disturbed and temporary cavities (“free volume”) are created between the elements, the number and size of which depend on the temperature. The glass transition temperature T_g0 defined in this way is a fixed material constant of the disordered (non-crystalline) state that is dependent only on the pressure. As a result of the increasing inertia of the molecular matrix when approaching T_g0, the setting of the thermal equilibrium is successively delayed, so that the usual measuring methods for determining the glass transition temperature in principle deliver T_g values that are too high. In principle, the slower the temperature change rate is set during the measurement, the closer the measured T_g value T_g0 approaches.^[21] Techniques such as dynamic mechanical analysis can be used to measure the glass transition temperature.^[22]

[…]

Glass is a “frozen liquid” (i.e., liquids where ergodicity has been broken), which spontaneously relax towards the supercooled liquid state over a long enough time.

Glasses are thermodynamically non-equilibrium kinetically stabilized amorphous solids, in which the molecular disorder and the thermodynamic properties corresponding to the state of the respective under-cooled melt at a temperature T* are frozen-in. Hereby T* differs from the actual temperature T.^[27]

Glass is a nonequilibrium, non-crystalline condensed state of matter that exhibits a glass transition. The structure of glasses is similar to that of their parent supercooled liquids (SCL), and they spontaneously relax toward the SCL state. Their ultimate fate is to solidify, i.e., crystallize.^[23]

On the scale of millions of years, everything flows.