Is IDX open on Monday 23 January 2012?

No. IDX is closed on Monday 23 January 2012 for Lunar New Year. It reopens on Tuesday 24 January 2012.

Lunar New Year

Related markets on 23 Jan 2012

TSE Tokyo	09:00–15:00
HKEX	Chinese New Year
SSE	Chinese New Year (Spring Festival)
KRX	Seollal (New Year's Day by the lunar)
NSE	09:15–15:30
SGX	Chinese New Year
ASX	10:00–16:00
NYSE	09:30–16:00
Nasdaq	09:30–16:00
TSX	09:30–16:00