Complex sentence: In particular, an important stone block text has been found dating to around 300 BC. It has been argued that this text celebrates a period completion of time to fall sometime between and 7.3.0.0.0 and 7.5.0.0.0--295 and 256 BCE, respectively.
Split into simpler sentences: In particular, an important stone block text has been found dating to around 300 BC. It has been argued that this text celebrates an upcoming time period ending celebration. This time period may have been projected to end sometime between and 7.3.0.0.0 and 7.5.0.0.0--295 and 256 BCE, respectively.