rule = ≥ (default)

edit
Code Main Sandbox
{{Interval|n=1|2|4|6}} 0-1 0-1
{{Interval|n=2|2|4|6}} 1-2 1-2
{{Interval|n=3|2|4|6}} 1-2 1-2
{{Interval|n=4|2|4|6}} 2-3 2-3
{{Interval|n=5|2|4|6}} 2-3 2-3
{{Interval|n=6|2|4|6}} 3-4 3-4
{{Interval|n=7|2|4|6}} 3-4 3-4

rule = >

edit
Code Main Sandbox
{{Interval|n=1|2|4|6|rule=>}} 0-1 0-1
{{Interval|n=2|2|4|6|rule=>}} 0-1 0-1
{{Interval|n=3|2|4|6|rule=>}} 1-2 1-2
{{Interval|n=4|2|4|6|rule=>}} 1-2 1-2
{{Interval|n=5|2|4|6|rule=>}} 2-3 2-3
{{Interval|n=6|2|4|6|rule=>}} 2-3 2-3
{{Interval|n=7|2|4|6|rule=>}} 3-4 3-4

Many numbers

edit
Code Main Sandbox
{{Interval|n=14|2|4|6|8|9|10}} 6-7 6-7

Example with timestamp

edit
Code Main Sandbox
{{interval}} 4-5 4-5

Invalid

edit
Code Main Sandbox
{{Interval|1|2|4|6}} 0-1 0-1