The 2nd of April is celebrated in Iranian society as Sizdah be dar, the last day of the New Year celebration. The day takes it’s roots from the time of the Persian Empire and signaled a return to normal life after the 12 previous days, which have been devoted to the New Year. Each day in the Persian calender was devoted to a deity and this particular day was to the god of rain, so it is still thought of as a good day to pray for rain.
Normally this is a time to pack a picnic and go to a park for day. It is believed that laughter and fun can drive away evil spirits and this is a good way to do so. Toward the end of the day it is traditional to throw peices of sabzeh in to a near by river. Sabzeth is lentils or sprouted wheat and may have been planted at the beginning of the New Year celebration.
Just as a side reference the 2nd of April corresponds to the 13th of Farvardin and Sizdah means 13 and de bar means “to get ride of”, so this means to get ride of 13.
Of course it will be a little late to take the day off, but try to take a moment or two to just enjoy today.