Saint Peter apparently was raised in the spring of 1918.
1918: This year is critical to current Watch Tower eschatology. Firstly, in the spring of 1918, the first resurrection commenced and the apostles and faithful anointed ones who had died were raised invisibly to heavenly life.
“The resurrection of the anointed Christians, who number 144,000, is to spirit life in heaven and it began to occur in 1918 C.E., after the establishment of the heavenly Kingdom in 1914.“ WT June 1, 1970 p. 331 "Faith to the Preserving Alive of the Soul”
“In 1918 he (the apostle Peter) was resurrected to the heavens along with the other faithful members of Christ’s congregation who had died prior to that time. “(WT February 15, 1966 p. 123 “Does Peter Now Use the Keys of the Kingdom?”
“Those who died prior to the establishment of the Kingdom were resurrected at the time of Jehovah's coming to the temple with his messenger of the covenant in 1918.” WT 67 8/1 p. 455 A New Administration of Earth's Affairs
“The Watchtower has long presented the view that this resurrection of anointed Christians from death commenced in the year 1918.” WT 86 10/1 p. 14 Comfort From the God of Peace
Curiously though, for close to 50 years prior to 1927, the Watch Tower Society, based on other eschatological calculations, taught that the first resurrection began in 1878.
In 1878 the process of setting up the kingdom began. The Lord raised the sleeping saints. WT 6/1/1922, p.174
Our Lord's resurrection occurred three and a half years after his advent as the Messiah, in A.D. 29; and the resurrection of his body, the Church, we have seen, was due in the year 1878, three and a half years after his second advent, in October 1874." Thy Kingdom Come p. 305
It was only in 1927 that that the date for the first resurrection was changed to 1918
"One of the many enlightening truths that God now gave his witnesses was about the members of God's spiritual nation who had died physically. This was in 1927. In that year the witnesses understood that the dead spiritual Israelites had been raised in 1918 to life in heaven with Christ Jesus. It was an invisible resurrection, of course." From Paradise Lost to Paradise Regained p.192