The 1e Forgotten Realms Campaign Set (1987) contains both Cyclopedia of the Realms, which opens with a letter dated at the end of the year:
The information presented herein is
as known to myself, those about me in
the lands north and west of the Sea of
Fallen Stars, and those I have encountered in my travels. On my word as a
sage nothing within these pages is false,
but not all of it may prove to be true. All
stories presented are as I have heard
them and had them recorded, all information is checked as best as possible
given the limited resources of an old
man in a small town (even if that old
man has the power to flatten mountains, mind you). As you adventure in
this fantasy world, be warned that not
all things are as they appear, and trust
to your wits, your weapons, and your
common sense in surviving and profiting from the Forgotten Realms.
As recorded by Lhaeo, Scribe to the
Sage, ELMINSTER OF SHADOWDALE,
30th and last day of Nightal, Year of the
Prince, 1357 Dalereckoning
Names for the years are known as the
Roll of Years, as they are drawn from
predictions written down under that
title by the famous Lost Sage, Augathra
the Mad, with a few additions by the
seer Alaundo (for further information
on Alaundo see entry under Candlekeep). The Roll is a long one; here is the
relevant portion of it.
YEAR OF THE PRINCE (1357 DR—year just ending).
In commemoration of that pact
man and elf raised the Standing Stone
which is now seen where the road from
Mistledale reaches the road from
Essembra to Hillsfar. It is from the raising of this Stone that Dalereckoning is
taken.
ELMINSTER'S NOTES: The Standing
Stone was erected 1357 years ago by
mighty elvish mages to commemorate
the pact between the Elvish Court and
the newly-arriving Dalemen. The winding script at the base of the Stone states
the terms of that pact: that while there
are elves in the forest, the men of the
dales may settle in those lands at their
borders, but not to reduce the wood or
invade elven territories.
And it contains DM's Sourcebook of the Realms:
Recent News and Rumors in the Realms
This section contains some of the gossip that came to the ears of the
inhabitants of the Northern Realms in
past two years; the Year of the Worm and
the Year of the Prince.
Year of the Worm
Dale Reckoning 1356
Hammer (January)
• There is fierce fighting in the
Sword Coast lands just south of Waterdeep. [...]
Year of the Prince
Dale Reckoning 1357
[...]
Nightal (December)
• The first heavy snowfall has swept
the North, blanketing Cormyr and the
Dales with up to a foot of snow. [...]
2e Forgotten Realms Campaign Setting (1993):
Dalereckoning (DR): Dalereckoning is taken from the year
that humans were first permitted by the Elven Court to settle in
the more open regions of the forests. The information within this
text is accurate to the close of 1367 DR. In some texts, primarily
those which do not have direct ties to Dales history, Dalereckoning is called Freemans Reckoning (FR).
The Roll of Years
The Year of the Shield (1367 DR, the year just ending)
3e Forgotten Realms Campaign Setting (2001):
The Roll of Years
Very few of Faerun's common folk bother with musty calendars and
meaningless numbers. Instead, years are known by names. For example, 1372 DR—the current year—is called the Year of Wild Magic. People refer to births, deaths, weddings, and other events by the name of the year. Children learn the order of the years from bards' songs, artistic designs in the great temples, and the teachings of their elders.
4e Forgotten Realms Campaign Setting (2008):
Ten Important Facts
The following points describe the biggest changes
to the world of Toril since the previous edition of
the FORGOTTEN REALMS Campaign Setting. If you are
familiar with the setting, these will summarize the
major events in the world since 1374 DR, the Year of
Lightning Storms. If you are new to the setting, this
information will give you the basic background that
most inhabitants know.
- Roughly a hundred years have passed in the world
since the previous edition of the campaign setting. The
current year is 1479 DR, the Year of the Ageless One.
In 5e Sword Coast Adventurer's Guide (2015), the current year is technically unstated but 1489 DR is described in a section named "A Brief History" which implies that it's in the past. That would mean 5e starts in 1490 at the earliest.
Early in 1487, earthquakes and volcanic eruptions abounded for months, as if the whole world was convulsing. Rumors spread of chasms caused by the Spellplague suddenly vanishing, and stories circulated of known destinations being farther away from one another, as if the world had quietly added miles of wilderness to the distance between them. Word began to spread of places and peoples not heard from since the Spellplague. It became apparent that some of the effects of that terrible time had been reversed.
By 1489, many of the wars that began during the Sundering had ground to a close. Other conflicts arose, and mighty threats still imperiled the world, but the deities ceased interfering with the world through their Chosen. The gods were no longer silent but quiet, and in many places new priesthoods arose to interpret the gods’ now subtle signs.
The world today seems a place filled with new lands and opportunities, where those who dare can leave their mark. Students of history and those elves and dwarves who recall the past that short-lived humans see as distant perceive a world much like it was over a century ago.
The early 5e adventure Princes of the Apocalypse (2015):
The people of the Forgotten Realms number the years by the Dalereckoning calendar, which is abbreviated "DR." Years are also given names, which are drawn from the writings of a great seer from long ago. The adventure is set in 1491 DR, the Year of the Scarlet Witch.
In the 5e adventure Baldur's Gate: Descent into Avernus (2019), the city of Elturel is taken away 'fifty years' after the Companion and its undead-destroying light appeared in the sky in 1444 DR, so it's set in 1494 DR.
Zariel never forgot her betrayers—those who ran from the battlefield. She kept a close eye on Elturel, waiting for the day when she could enact her revenge. That day came in 1444 DR, when Elturel was conquered by a vampire lord. A priest of Torm named Thavius Kreeg appealed to any power to help him save his holy city. In that instant, Zariel emerged from a pillar of fire and offered him a deal, which Thavius readily accepted.
