Is TWSE open on Friday 4 February 2011?

No. TWSE is closed on Friday 4 February 2011 for Chinese New Year. It reopens on Tuesday 8 February 2011.

Chinese New Year

Related markets on 4 Feb 2011

TSE Tokyo	09:00–15:00
HKEX	The second day of 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