Gamefaqs.com has an excellent battle mechanics guide. Here's what it has to say about Lancers:

Quote Originally Posted by Aerostar's Battle Mechanics Guide
Damage from a JUMP is calculated as follows:

If caster is equipped with any weapon, then

damage = [PA * K] * WP

If caster is barehanded, then

damage = [(PA * Br) / 100] * PA

where K = 3/2 if the caster is equipped with a spear
K = 1 otherwise

The JUMP directive will leave the caster in the air for a number
of clockticks, ctr:

ctr = [50 / (Jumper's Speed)]

This ctr value is unaffected by the 'Short Charge' and 'Non-Charge'
abilities. Haste status is ignored in this equation -- a Hasted
jumper will land in the same number of clockticks as an un-Hasted
jumper with the same Speed.

While JUMP is charging, the jumper cannot be a target. A jumper's
CT will still increase while he is in the air, although the counters
on time-dependent status effects will pause. Normal jumpers will land
with ~50 CT; Hasted jumpers will land with ~75 CT.