Hari Raya and Angpao/ Galak Gampil tradition
Younger families usually visit their older neighbours or relatives to wish and greet them a Happy Eid also to ask for forgiveness. During these visits, it is a customs for older, established or married couple to give uang lebaran, small amount of moneys for children's of their own, relatives' as well as neighbours'. Idul Fitri is a very joyous day for children as adults give them money in colourful envelopes. To cater for this customs, Indonesian Banks and Bank Indonesia usually open some money changer counters to change larger to smaller denominations several days prior to Lebaran. The denominations may vary from 1,000, 2,000, 5,000 to 10,000 rupiah.
(cited from wikipedia)