“Horae Serenae” by Sir Edward John Poynter
“The Horae’s themes are time and cycles. Their symbols are clocks, hourglasses and egg timers. These are the Greek and Roman Goddesses of time, ruling over the seasons and every hour if the day. They make sure that nature and life’s order is kept, and they generally strengthen our awareness of time and the earth’s cycles.
In the mid-1700s, Britain changed over from the Julian system to the Gregorian calendar. People went to sleep on Wednesday, September 2 and woke up Thursday, September 14, putting the Horae on notice that humans need help with scheduling! To evoke the Horae’s promptness in your life, try blessing your watch saying,
‘By the minute, by the hour, instill in me a sense of time;
by the season, by the year, renew the magic with this rhyme.’
Repeat this phrase and touch your watch any time you have to be punctual, meet a deadline or stat precisely on schedule for whatever reason. The Horae will then nudge you when you start to dilly-dally, lag behind or get otherwise distracted.
For keeping up with everyday, mundane tasks, this spell works for alarm clocks, bakery timers, hourglasses, water clocks and sun dials. Bless the token using the same incantation. Then attach a schedule or ‘to do’ list to any of these items on and around your home. This symbolically attaches the Horae’s timeliness to those areas, enhancing your productivity levels.”
(Patricia Telesco, “365 Goddess: a daily guide to the magic and inspiration of the goddess”.)
“Horai: Autumn” by *iizzard
The earliest written mention of horai is in the Iliad where they appear as keepers of Zeus‘s cloud gates. ‘Hardly any traces of that function are found in the subsequent tradition,’ Karl Galinsky remarked in passing. They were daughters of Zeus and Themis, half-sisters to the Moirai.” 
Patricia Monaghan writes: “Also called the ‘hours’ or the ‘seasons,’ They were a group of Greek Goddesses and, like other groups, appeared in various numbers. Sometimes there were two of them: Thallo (‘spring’) [or ‘new shoots’] and Carpo (‘autumn’) [or ‘fruit’] [and Auxo (‘spring growth’) that would make three as the Greeks had only three seasons; spring, summer and winter]. Sometimes there were three: Eunomia (‘lawful order’), Dike (‘justice’), and Irene (‘peace’). They were the Goddesses of the natural order, of the yearly cycle, of plant growth; They ruled the varied weather of the seasons. By extrapolation They became the Goddesses who ruled the order of human society.
Few legends were told of them, although They made cameo appearances in Olympian celebrations and myths of other Goddesses – clothing the newly born Aphrodite, for example, dancing with the Graces, or opening the gates of heaven for Hera‘s escapes to solitude. Only Dike had an actual myth to Her name. The younger self of Her mother Themis – as Hebe was of Hera and Persephone of Demeter – She grew so weary of the constant wars of humankind that She withdrew to the mountains, to await a more peaceful order. Ages passed, and conditions grew worse instead of better. Finally Dike, losing hope in humanity, ascended to heaven to become the constellation Virgo” (p. 155 – 156).
“Apollo and the Hours” by Georg Friedrich
“Another set of Horai personified the twelve hours of the day.” 
“The Twelve Horai (or Horae) were Goddesses of the hours of the day and perhaps also of the twelve months of the year. They oversaw the path of the sun-god Helios as he travelled across the sky, dividing the day into its portions.
The ancient Greeks did not have hours of fixed length like we do today. Instead they divided the hours of daylight into twelve portions, identified by the position of the sun in the sky. Thus the length of the hour varied between the longer days of summer and shorter ones of winter.
The twelve Horai were not always clearly distinguishable from the Horai of the seasons, who were also described as overseeing the path of the sun.”  Wikipedia lists the Twelve Horae:
- Auge, first light
- Anatole or Anatolia, sunrise
- Mousika or Musica, the morning hour of music and study
- Gymnastika, Gymnastica or Gymnasia, the morning hour of gymnastics/exercise
- Nymph, the morning hour of ablutions (bathing, washing)
- Mesembria, noon
- Sponde, libations poured after lunch
- Elete, prayer, the first of the afternoon work hours
- Akte, Acte or Cypris, eating and pleasure, the second of the afternoon work hours
- Hesperis, evening
- Dysis, sunset
- Arktos, night sky, constellation
Monaghan, Patricia. The New Book of Goddesses and Heroines, “Horae”.
Theoi Greek Mythology, “The Horai“.
Theoi Greek Mythology, “Horai“.
Tuccinardi, Ryan. Encyclopedia Mythica, “Horae“.