In the world of Faerun, the people commonly use the Harptos Calendar to keep a track of time.

The Basics:

The calendar has twelve
months of thirty days plus a few additional "feast days" often
marking important occasions. The calendar is broken down into four seasons:
Summer, Fall, Winter and Spring. 

The map was made (and named after) a wizard called Harptos of Kaalinth. 

Each month has two names, the Common form (English terminology) and the Chondathan from.

The reason for the Chondathan forms is because Harptos hailed from Kaalinth, a keep on the north coast of Tethyr, which now lies in ruin. And the language spoken in this region is generally Chondathan, while Common is simply the trading tongue.

Common: 

• Deepwinter
• Claw of Winter
• Claw of Sunsets
• Claw of Storms
• The Melting
• The Time of Flowers
• Summertide
• Highsun
• The Fading
• Leaffall
• The Rotting
• The Drawing Down

Chondathan:

Chondathan is a common tongue spoken within the Forgotten Realms, specifically West Faerun. 

• Hammer (HAM-mer) using IPA:  /'hæm.mɜr/ 
• Alturiak (awl-TUHR-iak) using IPA: /ɔ:l.'tɜ:r.iæk/ 
• Ches using IPA:  /t͡ʃes/
• Tarsakh (TOUR-sakh) using IPA:  /'tɑ:r.sæx/ 
• Mirtul (MUHR-tul) using IPA:  /'mɜr.təl/
• Kythorn (KAI-thorn) using IPA:  /'kɑɪ.θʊrn/
• Flamerule (FLEYM-rool) using IPA:  /'flɛɪm.ru:l/ 
• Eleasis (eh-LEE-sis) using IPA:  /ɛ.'lis.ɪs/
• Eleint (eh-LAYNT) using IPA: /ɛ.'lɛɪnt/
• Marpenoth (MAR-pen-oth) using IPA:  /'mær.pɛn.ɔð/
• Uktar (uk-TAR) using IPA: /ʊk.'tær/
• Nightal (NAI-tal) using IPA:  /'næi.tæl/

Using the Calendar

Having a calendar can be useful in keeping a track of the passage of days. 

For example, in Faerun, each month is broken up into three "tendays" - their form of a week. The months are also full of different feast days and holidays that your
characters could potentially participate in. 

Not only is this a fun way to mix-up a "shopping episode" and give your characters interesting and eclectic NPCs they wouldn't necessarily meet outside of a festival. It allows for the world to feel just a little bit more fleshed out and lively. The evening before a big celebration, for example, locals might be spotted setting up candles or flags. There might be a special holiday greeting the locals use as well. 

This calendar is perfect for Game Masters preparing to run an adventure module set in the Sword Coast such as "Waterdeep: Dragon Heist" or "Icewind Dale: Rime of the Frostmaiden".

How to say the Calendar Months in Elvish

• Kae-Auglath "deep winter" (KEI-aug-lath)
• Velbrin Iauglath, often shortened to: N'iaughlath "claw of winter" (nuh-ee-AUG-lath)
• Velbrin Iarzu, often shortened to: N'iarzu "claw of sunset" (nuh-ee-AR-zu)
• Velbrin Iarrna, often shortened to: N'iarrna "claw of storms" (VEL-bri-ARR-nah)
• Tath Alusuth "the melting"
• Ilfellath "the time of flowers" (il-fel-lath)
• Evaellathull "summertide" (ev-AEL-lath-UEL)
• Alurar "highsun" (al-UR-ar)
• Tath Vaneth "the fading" (tath VA-neth)
• Ileldyon "leaffall" (il-EL-dyon)
• Tath Mhaoth "the rotting" (tath muh-HOWTH)
• Tath Zuth "the drawing down" (tath ZOOTH)

For the super nerdy- here's how it all breaks down.

The first aspect of this word is "deep / intense" written: Kae / Kë / Cae. This comes from the term "Es'Caerta", which is officially a: "Deeply Emotional Plea Ending A Prayer". As this is a plea, we know it means something! Here's how it breaks down:

• es' - a prefix relatived to: es "to prepare" or ēs "to ward", and is used to mark a prayer or faith-based spell
• kae, keï "deep / intense (emotions)"
• ir "to draw from water" - related to word for sea "iuma"
• []ta "we hope to []"

Thus this phrase could be something like: In this prayer, we hope to draw from a well of deep emotion!

For this reason, we can say Kae is the adjective mean "deep or intense (emotions)".

With Elvish, slight changes in stress can alter the meaning of a word. Keauglath, would usually be pronouned "kei-AUG-lath" but that instead it's "KEI-aug-lath". This informs the listener that it's not deep emotions but a deep concept / thing.

Now for the second aspect, Auglath. This one is a bit simpler! It comes from the old elvish family name Auglathla. From other Elvish words it's clear that Lath means "a period of time" when used as a suffix. The verb la means "to sway" and works nicely as a way to say "breeze" - i.e. a swaying. Therefore Auglath is the Elvish word for winter.

Elvish doesn't have an official term for "claw", so I have created one. Velbrin combines the ideas of "vel" which means blade and "brin" fist, i.e. "the blade of the fist".

As discussed above, Auglath means winter. The "i" at the beginning makes this genitive class, of winter.

To shorten the name of the month, Elves would likely say N'iaughlath. This is in part because Velbrin ends with an N. But also, the prefix N' is often attached to Elvish words to twist the original meaning. Native speakers would understand that N'iaughlath means Claw of Winter, though really it's most literally translated as Odd Winter.

This one is pretty simple! The Elvish word for "sunset" is Arzu. Add the N'i element as above.

Once again, the Elvish word for "storm" is Arrn (plu. Arrna). We know this from the spell "arrn tel orar" Storm Erosion and the term "arrn’ess" Storm Bringer.

The Elvish definite article Tath works a little differently to English's "the". It is generally there to place emphasis or to establish a proper noun - such as here. Think of it like changing it from melting to Melting.

As for the term Alusuth, this comes from the Elvish word alus "water". The verb alusu means "to become water" i.e. "to melt". The final "-th" is just like English's "-ing" ending.

Ilphel / Ilfel is one of the many Elvish words for flower.

Lath as a suffix means "a period of time"

For a direct translation you could say Tath Lath Īphela, however there is potential for confusion as this could also mean "The Day of Flowers". The shorter form is more direct.

Evaellath means "Summer" in Elvish. I create this word by combining two known elements. The Lath suffix I've discussed already. So let's talk about Evael. This directly means "intensity" but has close ties with heat and fire. We know this because Evaelathil can be translated as "Flamebane" or "Nemesis of Intensity".

The final element is usually written yyll / ӯll. This is one of those hard to translate Elvish words. It generally either refers to the sun's path in the sky or other elements of time such as fate and history. I use this suffix because "tide" means "time".

How I got to "yll":

Yyllethyn, a breed of horse. The term is usually translated as "Sun-Follower", however, the standard word for "sun" is ar.

Nharaigh Lathanyl, "noontime sunlight".

Y'landrothiel, "the traveler's star", and Y'tellarian, "the far star".

Because the Elvish word for "high" and "sun" are both ar, I have used an alternative adjective: Alur, means "highest, best, elevated". Therefore Alurar means "Elevated Sun".

The word Vane(th) comes from be slowly peeling back the word Vanessari "to disappear, to go invisible". The shorter form Vane means "to hide, to fade".

The Elvish word for "leaf" is dyon (plu. dyona).

The element ilel I took from the term ileleste "falling rain, rainfall". The L ending of ilel makes this element look like a verb - hence "fall". The element este is therefore "rain".

The word for "rotting" I took from the Elvish word for "corruption", mhaor. Removing the final R, I turned this into a verb meaning "to corrupt, to rot, to rust".

The verb zu comes from the same word I mentioned earlier, arzu "sunset". Ar of course means "sun" so zu means "to set, to go down". Thus this month is literally: The Setting, the Going Down. And this felt like it had the same essence as the original term.