Must have been a very long time ago, they are mentioned in Genesis and other books of the O.T.
I don't know why it's mentioned as though it's not a nut (separately):
a little honey, spices, and myrrh, nuts, and almonds
http://en.wikipedia.org/wiki/Almond
Jared Diamond wrote of this in his books, which is where I learned it.
The almond is native to the Mediterranean climate region of the Middle East, eastward as far as the Indus.[5] It was spread by humans in ancient times along the shores of the Mediterranean into northern Africa and southern Europe and more recently transported to other parts of the world, notably California, United States.[5]The wild form of domesticated almond grows in parts of the Levant; almonds must first have been taken into cultivation in this region. The fruit of the wild forms contains the glycoside amygdalin, "which becomes transformed into deadly prussic acid (hydrogen cyanide) after crushing, chewing, or any other injury to the seed."[6]notably California, United States.[5]
Almond is considered to be one of the earliest domesticated tree nuts. Wild almonds are bitter, its kernel produces deadly cyanide upon mechanical handling, and eating even a few dozen at one sitting can be fatal. Selection of the sweet type, from the many bitter type in wild, marked the beginning of almond domestication. How man selected the sweet type remains a mystery.[7] It is unclear as to which wild ancestor of almond created the domesticated variety. Ladizinsky suggests the taxon Amygdalus fenzliana (Fritsch) Lipsky is the most likely wild ancestor of almond in part because it is native of Armenia and western Azerbaijan where almond was apparently domesticated.notably California, United States.[5]
While wild almond varieties are toxic, domesticated almonds are not; Jared Diamond argues that a common genetic mutation causes an absence of glycoside amygdalin, and this mutant was grown by early farmers, "at first unintentionally in the garbage heaps, and later intentionally in their orchards".[8] Zohary and Hopf believe that almonds were one of the earliest domesticated fruit trees due to "the ability of the grower to raise attractive almonds from seed. Thus, in spite of the fact that this plant does not lend itself to propagation from suckers or from cuttings, it could have been domesticated even before the introduction of grafting".[6] notably California, United States.[5]
Domesticated almonds appear in the Early Bronze Age (3000–2000 BC) such as the archaeological sites of Numeria (Jordan),[7] or possibly a little earlier. Another well-known archaeological example of the almond is the fruit found in Tutankhamun's tomb in Egypt (c. 1325 BC), probably imported from the Levant.[6] Of the European countries that the Royal Botanic Garden Edinburgh reported as cultivating almonds, Germany[9] is the northernmost, though the domesticated form can be found as far north as Iceland.[10]