Caution
This data pack is highly dependent on the internal implementation details of Minecraft and may not work in future versions.
Calculates the current value of the JVM's high-resolution time source in milliseconds ((System.nanoTime() / 1000000L) & 0x0000ffffffffffff).
# Initialize once.
function get_millis:init
# Get the millis. The execution position must be loaded to place the template.
execute positioned 0 0 0 run function get_millis:
# The result is split into high 32 bits (#millis[63:32] get_millis)
# and low 32 bits (#millis[31:00] get_millis).
tellraw @s [ \
{"score": {"name": "#millis[63:32]", "objective": "get_millis"}}, \
", ", \
{"score": {"name": "#millis[31:00]", "objective": "get_millis"}} \
]