Year of next shieldmeet? [Archive] - Wizards Community

Year of next shieldmeet? [Archive] - Wizards Community

Post/Author/DateTime Post
Alisttair
07-30-04, 03:15 PM Which year will have the next shieldmeet after 1372DR???
ruleslawyer
07-30-04, 03:30 PM Shieldmeet's like leap year; it's the way of accounting for the extra quarter day every year. So, it's in every fourth year, meaning that the next Shieldmeet is in 1376 DR.
FriendOfReligion
08-05-04, 04:04 PM This is a borderline cosmology question, but since it concerns the calender more than the planet, I'm posting it here.

Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons.

On most of Earth the problem was solved fairly well by the Gregorian calendar, which makes centruy yeaars leap years only if they are evenly divisible by 400. 2000 was a leap year, but 1900 wasn't nor will be 2100. (If you didn't celebrate February 29, 2000 in a big way, you really missed the boat -- it was a holiday which only occurs once every 400 yerars.)

The Gregorian calendar is accurate to within a few seconds a year; the Julian calendar, which it replaced in most areas, had drifted so much that Russia's "October Revolution" took place in November, according to the calendar used in most other countries. A drift that severe could really mess up some of the festivals in Faerun.

Maybe that's what will bring Amauntor back from the dead: a PC quest to make an accurate calendar.
Kuje31
08-05-04, 05:33 PM Originally posted by FriendOfReligion
This is a borderline cosmology question, but since it concerns the calender more than the planet, I'm posting it here.

Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons.

365 total.

I'm not sure on the 1/4th part but there is always 30 days in a month, hence each week is a tenday and there is three tendays in a month. And there's 12 months to a year, plus the 5 holidays that are celebrated across all of faerun...... to equal 365.
Jerryd
08-05-04, 08:19 PM Originally posted by FriendOfReligion
Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons.
Yes, the tropical year has to be exactly 365 1/4 days, but not only to keep the seasons in synch, but also to keep the moon in synch. The synodic period of Selune is exactly 30.4375 days. The synodic period is dependent on the year length, because it goes from full moon to full moon - i.e. it takes into account not just how long it takes Selune to circle Toril but how much extra time it takes to catch up by the amount Toril has moved in it's own orbit. (The period it takes a moon to circle its primary in relation to the stars and without taking into account the motion of the primary is called the siderial period.) Since it's stated that there are exactly 48 synodic months (1461 days exactly) in four calendar years (FRCS,p.230) and that Selune is full at exactly every midnight on the first day of every leap year, then the tropical year has to be exactly 1461 / 4 = 365.25 days long. The Shieldmeet day is the mechanism by which the calendar months are kept from drifting through the seasons.

Edit: Actually, I may have confused tropical and siderial years there, but the point remains. They're all mathematically related.
FriendOfReligion
08-22-04, 03:47 PM Originally posted by Jerryd
Yes, the tropical year has to be exactly 365 1/4 days, but not only to keep the seasons in synch, but also to keep the moon in synch. The synodic period of Selune is exactly 30.4375 days. The synodic period is dependent on the year length, because it goes from full moon to full moon - i.e. it takes into account not just how long it takes Selune to circle Toril but how much extra time it takes to catch up by the amount Toril has moved in it's own orbit. (The period it takes a moon to circle its primary in relation to the stars and without taking into account the motion of the primary is called the siderial period.) Since it's stated that there are exactly 48 synodic months (1461 days exactly) in four calendar years (FRCS,p.230) and that Selune is full at exactly every midnight on the first day of every leap year, then the tropical year has to be exactly 1461 / 4 = 365.25 days long. The Shieldmeet day is the mechanism by which the calendar months are kept from drifting through the seasons.

Edit: Actually, I may have confused tropical and siderial years there, but the point remains. They're all mathematically related.

Good obs! I didn't even think to work from the statement about the moons in four years. It's a very elegant creation, eh what? My own campaign world orbits a red giant and has a tropical year equal to approximately 32 Earth years. The place needs to be magic rich just to sustain crops through an "eight year spring" and "eight year winter." It is so fun though, watching the faces of players when NPCs accost them with statements like, "How could you not have know better than to do that? You must be at least nine months old!" or "Hey meester. Wanna meet my seester? She's almost six months old."

Post/Author/DateTime	Post
Alisttair 07-30-04, 03:15 PM	Which year will have the next shieldmeet after 1372DR???
ruleslawyer 07-30-04, 03:30 PM	Shieldmeet's like leap year; it's the way of accounting for the extra quarter day every year. So, it's in every fourth year, meaning that the next Shieldmeet is in 1376 DR.
FriendOfReligion 08-05-04, 04:04 PM	This is a borderline cosmology question, but since it concerns the calender more than the planet, I'm posting it here. Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons. On most of Earth the problem was solved fairly well by the Gregorian calendar, which makes centruy yeaars leap years only if they are evenly divisible by 400. 2000 was a leap year, but 1900 wasn't nor will be 2100. (If you didn't celebrate February 29, 2000 in a big way, you really missed the boat -- it was a holiday which only occurs once every 400 yerars.) The Gregorian calendar is accurate to within a few seconds a year; the Julian calendar, which it replaced in most areas, had drifted so much that Russia's "October Revolution" took place in November, according to the calendar used in most other countries. A drift that severe could really mess up some of the festivals in Faerun. Maybe that's what will bring Amauntor back from the dead: a PC quest to make an accurate calendar.
Kuje31 08-05-04, 05:33 PM	Originally posted by FriendOfReligion This is a borderline cosmology question, but since it concerns the calender more than the planet, I'm posting it here. Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons. 365 total. I'm not sure on the 1/4th part but there is always 30 days in a month, hence each week is a tenday and there is three tendays in a month. And there's 12 months to a year, plus the 5 holidays that are celebrated across all of faerun...... to equal 365.
Jerryd 08-05-04, 08:19 PM	Originally posted by FriendOfReligion Is the tropical year of Abeir-Toril exactly 365 1/4 days long, or is it shorter or longer? I'm curious because if it isn't exactly 365 1/4 days, the annual Shieldmeet day should force the calendar to drift, with the months no longer matching the seasons. Yes, the tropical year has to be exactly 365 1/4 days, but not only to keep the seasons in synch, but also to keep the moon in synch. The synodic period of Selune is exactly 30.4375 days. The synodic period is dependent on the year length, because it goes from full moon to full moon - i.e. it takes into account not just how long it takes Selune to circle Toril but how much extra time it takes to catch up by the amount Toril has moved in it's own orbit. (The period it takes a moon to circle its primary in relation to the stars and without taking into account the motion of the primary is called the siderial period.) Since it's stated that there are exactly 48 synodic months (1461 days exactly) in four calendar years (FRCS,p.230) and that Selune is full at exactly every midnight on the first day of every leap year, then the tropical year has to be exactly 1461 / 4 = 365.25 days long. The Shieldmeet day is the mechanism by which the calendar months are kept from drifting through the seasons. Edit: Actually, I may have confused tropical and siderial years there, but the point remains. They're all mathematically related.
FriendOfReligion 08-22-04, 03:47 PM	Originally posted by Jerryd Yes, the tropical year has to be exactly 365 1/4 days, but not only to keep the seasons in synch, but also to keep the moon in synch. The synodic period of Selune is exactly 30.4375 days. The synodic period is dependent on the year length, because it goes from full moon to full moon - i.e. it takes into account not just how long it takes Selune to circle Toril but how much extra time it takes to catch up by the amount Toril has moved in it's own orbit. (The period it takes a moon to circle its primary in relation to the stars and without taking into account the motion of the primary is called the siderial period.) Since it's stated that there are exactly 48 synodic months (1461 days exactly) in four calendar years (FRCS,p.230) and that Selune is full at exactly every midnight on the first day of every leap year, then the tropical year has to be exactly 1461 / 4 = 365.25 days long. The Shieldmeet day is the mechanism by which the calendar months are kept from drifting through the seasons. Edit: Actually, I may have confused tropical and siderial years there, but the point remains. They're all mathematically related. Good obs! I didn't even think to work from the statement about the moons in four years. It's a very elegant creation, eh what? My own campaign world orbits a red giant and has a tropical year equal to approximately 32 Earth years. The place needs to be magic rich just to sustain crops through an "eight year spring" and "eight year winter." It is so fun though, watching the faces of players when NPCs accost them with statements like, "How could you not have know better than to do that? You must be at least nine months old!" or "Hey meester. Wanna meet my seester? She's almost six months old."