Genie Lamps giving somekind of benefits to your character – on certain days of calendar... Best way is: to collect all genie lamps after use for your needs..
But on certain days of the month it may release a genie that inflicts a very serious status effect on the character it is used on (along with the benefit). Be careful when using the lamps.

Stone: Friday Days 5, 26
Death: Saturday Days 13, 27
Eradication: Sunday Days 7, 21

January 01 – 07 : +1 Might
January 08 – 14 : +2 Might
January 15 – 21 : +3 Might
January 22 – 28 : +4 Might

Febuary 01 – 07 : +1 Intellect
Febuary 08 – 14 : +2 Intellect
Febuary 15 – 21 : +3 Intellect
Febuary 22 – 28 : +4 Intellect

March 01 – 07 : +1 Personality
March........ goes like up

April 01 – 07 : +1 Endurance
April ....... goes like up

May 01 – 07 : +1 Accuracy
May ........ goes like up

June 01 – 07 : +1 Speed
June ........ goes like up

June 01 – 07 : +1 Luck
July ........ goes like up

August 01 – 07 : 1000 Gold
August 08 – 14 : 2000 Gold
August 15 – 21 : 3000 Gold
August 22 – 28 : 4000 Gold

September 01 – 07 : 05 Food
September 08 – 14 : 10 Food
September 15 – 21 : 15 Food
September 22 – 28 : 20 Food

October 01 – 07 : 2 Skill Points
October 08 – 14 : 4 Skill Points
October 15 – 21 : 6 Skill Points
October 22 – 28 : 8 Skill Points

November 01 – 07 : 2500 Experience
November 08 – 14 : 5000 Experience
November 15 – 21 : 7500 Experience
November 22 – 28 : 10000 Experience

December 01 – 07 : 1 Random Resistance
December 08 – 14 : 2 Random Resistance
December 15 – 21 : 3 Random Resistance
December 22 – 28 : 4 Random Resistance