What date the emancipation proclamtion?
It went into effect on January 1st, 1863.
No slaves were freed, immediately, by the Emancipation Proclamation. The Proclamation applied only to slaves held in territory then in rebellion against the United States. Those places were not subject to US law because they were in rebellion and keeping the Union forces out. The Proclamation only freed slaves as the Union forces moved forward and captured new Confederate territory after it was signed.
The Emancipation Proclamation only freed slaves that were held in states that were in rebellion- that is, the states that had seceded and joined the Confederacy. President Lincoln was unable to free slaves in the non-rebel states because the Constitution contains language that indicates slavery was acceptable. Only an amendment to the Constitution could fully abolish slavery- and that's what happened at the end of 1865 when the 13th Amendment was ratified.
When the union troops were in an area they often had the freed slaves come to them for protection and to help. At one point slaves came to one unit and the confederate officer demanded the return of the slaves from the union commander. The union commander told the Confederate that the slaves were contraband. By declaring them contraband he didn't have to return the slaves. After that event they called themselves "contraband."