A poem by Rumi's son, Sultan Valad*, recording the occasion of the passing of Rumi on December 17, 1273:

In commemoration of the Urs, the wedding with the Beloved, of 
Jalalu'ddin Rumi (the Urs is known in Persian as "vesal", "reunion 
[with the Beloved]"), 
A poem by Rumi's son, Sultan Valad*, recording the occasion of the passing of Rumi on December 17, 1273:

From this foul, fulsome world, Rumi moved on
After ten sweet years with Hosam al-Din*

On a December's day, the seventeenth*
came to pass that proud monarch's moving on
Of years six hundred seventy and two
since the Hijra of the Prophet* had gone by

The eye of mankind wept so sore that day
its lightning struck and burned away the souls
A quaking overtook the earth that moment
in the heavens rose a wail of mourning

The people of the town, both young and old
wailed and wept and sighed in lamentation

The villagers nearby, both Greeks and Turks
in pain upon his loss rent wide their collars
all paid the corpse their last loving respects

Folks from every faith proved faithful to him
in love with him the people of all nations

~ by Rumi's son, Sultan Valad
From Sultan Valad's "Valad nameh" (Persian, "The
Book of Valad), also known as "Ebteda nameh"
Translation by Professor Franklin D. Lewis
"Rumi, Past and Present, East and West"
Oneworld Publications, Oxford, 2000

* Hosam al-Din -- a sufi shaykh in his own right, Hosam al-Din acted
as Rumi's scribe, editor, and inspiration during the writing of the
Mathnawi. It's interesting to learn that the composition of the
Mathnawi was suspended when Hosam al-Din's wife died and he was
withdrawn in mourning. He also acted as an administrator of Rumi's
school in Konya.
* "December 17th" -- the Christian calendar equivalent of the fifth
day of Jumadi II. "Jumadi II" is the sixth month of the Arabic lunar
calendar.
* Seventy two and six hundred years since the Hijra of the Prophet --
"Hijra" (Arabic), the flight of the Prophet Muhammad from Mecca (in
Sept., 622 A.D. per the Christian calendar) to Medina. The Muslim
calendar dates from the first day of the hijra.