This is because festival of Hanukkah (which the second coin commemorates) occurs in December just before the new Gregorian year. Because of this they are assigned a Gregorian year with a deference of 3761 from the Hebrew year as opposed to the standard 3760.
For those that do not understand how the Hebrew calendar works this can be hard to properly describe. I hope what I wrote makes some sense.
The Hebrew calendar year begins on Rosh Hashanah which generally occurs during the month of September or October. Since the Hebrew calendar does not begin on January 1 nor end on December 31, the Hebrew year will span two Gregorian years. (Or conversely, the Gregorian year will span two Hebrew calendar years.) For example, the year 2004 will span the Hebrew calendar years 5764-5765. The year 5764 began on the eve of September 26, 2003 and ends on September 14, 2004. On September 15, 2004 the year 5765 begins.
Also, both the coins are from Israel, not palestine. Not sure why that was used in title.
As a side note, British Mandate Palestine coins used gregorian dating so this would not be relevant to those coins.
the Palestinian authority has fantasy coins as well. But these 2 coins you mention are clearly israeli.
