Can't really tell, that's not really how it works... Context is the key to the metaphor. Search for confirmation via multiple encodings of the same knowledge in different metaphors, geometry of word, etc. Each occultist may encode their knowledge with different terms.
Often a single day represents one's entire life (or the life of the Reaction [Re=sun god]. Sometimes this is also a heartbeat or heart, esp. if a God is measuring the man, such as in the Under World of Duat, with one's heart measured on a scale of Thoth (knowledge of balance) against the feather of Ma'at (order).
Other times a heartbeat is merely the observance of VIability, one of the 6 tallies of life. VI = 6, the number of (cosmic) order, as in VItality, VIbration, and VIkings, etc. Heart = Hearth = Heareth = Hertz (to modern science). However, many clocks exist so cycles per second isn't a good understanding, it's the principle that matters. Resonance of a material may be a clock via the measure of its heartbeat...
One set of symbolism does not typically hold universally among occultists encoding their knowledge of Alchemy. For instance, Jade is not penis in the "Jade Purity" of the east.
Many religions that are seemingly not alchemical are, in fact, occulted alchemical texts. Khem is the black land of "Egypt", known for its fertility and high mineral content. Allah Khem = God of such magic and thus source of Alchemy.
As an entry level example: The feathers atop the stave of Hermes represents activated electro-magnetic field; Such as a coil within a coil connected to a pulsed voltage source. This is a "Tesla Coil" to the mundane, a the Djed Tower in (not very well occulted) Egyptian symbolism; Djed towers have the same coils within coils and the All Seeing Eye of Wedjat -- radar, AKA Ra-Dark (the magic (11th letter) K is silent as in Knight), ergo the dark (unseen) power of the sun god, ergo Dark Ra = Radio = Ra-Deus, etc. Thoth, as a monkey, on the depiction of the "Dendra Lightbulb" has the solar disk of light above his head (instructing us to think of light); Thoth forms his hands in the shape of the Djed Tower that is illuminating the serpent in that "Nixie tube". Heartbeats in reference to such knowledge would be the VIbration of the quintessential field... or EM flux.
However, in the Hindu occult it is many arms, not feathers, that depict the EM field and power to touch from afar. Hint: As the Twin Towers of Boaz and Jachin or the Towers of Thor or the Djed Towers of Egypt, etc. radio sources overlap they form the Vesica Piscis and create "life" as in a fireball called a "maser effect" in modern science. Lower wavelength (slower heartbeat) radio can thus pass through walls and converge into higher frequency microwave at a single point. This convergence is key otherwise you only get microwave weapons that can't pass through walls well...
Take the story of the Basilisk, for example, as it occults the story of Alchemists being burned as witches and heretics: A Hen with the appearance of a Rooster (a Cock & male/female symbol of Hermes) lays an egg. The townspeople of Basil are said to put the chicken on trial lest it hatch a basilisk (an evil monster), as an apparently male chicken must not be able to lay eggs. The rooster has Black, Red, Yellow & White (the hidden rainbow of alchemy, i.e, black-body radiation generating light via adding red, then green, then blue). Thus, it is clearly the alchemist who is on trial -- The Basilisk story is a witch hunt. Such witch hunting is why much alchemical knowledge was and is kept occulted (hidden) in symbolism.
TL;DR: The metaphors and symbolism used depends on the occultist and/or school of alchemy that encodes the alchemical wisdom. Similarity among symbols between alchemical texts are for entry level understanding so that the apprentice may use their existing knowledge to begin to decode and understand the potentially vastly different symbolism in use that occults the higher level knowledge. See: the "two towers" symbolism above.