Hi all, I see a mismatch when using %Y format specifier with as::ftime. It looks like it outputs the year according to the week of the year. I hope I didn't miss or misunderstand anything... please find my small test program attached for reference. It was compiled as follows: g++ -g -Wall -I /opt/boost/1.55/include -L /opt/boost/1.55/lib -lboost_locale -lboost_thread -lboost_system -licuuc -licui18n -licudata -lpthread -lrt boost_dates_test.cpp I am running on Debian Testing: $ ldd a.out linux-vdso.so.1 (0x00007fffa39fe000) libboost_locale.so.1.55.0 => /opt/boost/1.55/lib/libboost_locale.so.1.55.0 (0x00007fba3335b000) libboost_thread.so.1.55.0 => /opt/boost/1.55/lib/libboost_thread.so.1.55.0 (0x00007fba33142000) libboost_system.so.1.55.0 => /opt/boost/1.55/lib/libboost_system.so.1.55.0 (0x00007fba32f3e000) libicuuc.so.52 => /usr/lib/x86_64-linux-gnu/libicuuc.so.52 (0x00007fba32ba2000) libicui18n.so.52 => /usr/lib/x86_64-linux-gnu/libicui18n.so.52 (0x00007fba3279a000) libicudata.so.52 => /usr/lib/x86_64-linux-gnu/libicudata.so.52 (0x00007fba30f2c000) libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fba30d0f000) librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fba30b07000) libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fba307fb000) libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fba304fa000) libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fba302e4000) libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fba2ff3a000) libboost_chrono.so.1.55.0 => /opt/boost/1.55/lib/libboost_chrono.so.1.55.0 (0x00007fba2fd34000) libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fba2fb2f000) /lib64/ld-linux-x86-64.so.2 (0x00007fba33642000) The program shows the output of cout<