Easter was the Sunday after the 15th day of this moon, whose 14th day was allowed to precede the equinox. Where the two systems produced different dates there was generally a compromise so that both churches were able to celebrate on the same day. By the 10th century all churches (except some on the eastern border of the Byzantine Empire) had adopted the Alexandrian Easter, which still placed the vernal equinox on 21 March, although Bede had already noted its drift in 725—it had drifted even further by the 16th century.
What did churches do to settle the date if there was a difference? 
compromise

Under Article IV, Section Three of the United States Constitution, which outlines the relationship among the states, Congress has the power to admit new states to the union. The states are required to give "full faith and credit" to the acts of each other's legislatures and courts, which is generally held to include the recognition of legal contracts, marriages, and criminal judgments. The states are guaranteed military and civil defense by the federal government, which is also obliged by Article IV, Section Four, to "guarantee to every state in this union a republican form of government".
What does Article 4, Section 4 guarantee?
guarantee to every state in this union a republican form of government

All of the state frequently experiences temperatures above 100 °F (38 °C) or below 0 °F (−18 °C), though below-zero temperatures are rare in south-central and southeastern Oklahoma. Snowfall ranges from an average of less than 4 inches (10 cm) in the south to just over 20 inches (51 cm) on the border of Colorado in the panhandle. The state is home to the Storm Prediction Center, the National Severe Storms Laboratory, and the Warning Decision Training Branch, all part of the National Weather Service and located in Norman. Oklahoma's highest recorded temperature of 120 °F (49 °C) was recorded at Tipton on June 27, 1994 and the lowest recorded temperature of −31 °F (−35 °C) was recorded at Nowata on February 10, 2011.
Where is the Storm Prediction Center located?
Norman