  Studies of the rotation and activity of M type stars are essential to enhance
our understanding of stellar dynamos and angular momentum evolution. Using the
outstanding photometric capabilities of space telescopes rotation signals even
with low amplitudes can be investigated in up to now unrivaled detail. By
combining data of K2 and the TESS prime mission the star spot activity of M
dwarfs can be monitored on half a decade timescale. In the framework of our
study on the rotation-activity relation for bright and nearby M dwarfs we also
aim at an investigation of the long-term activity. While K2 was observing
fields distributed around the ecliptic plane, the TESS prime mission was
oriented along a line of ecliptic longitude with one camera centered on an
ecliptic pole. Due to these different observing strategies, the overlap between
K2 and the TESS prime mission is marginal. However, 45 stars from our sample
were observed with both missions of which two early M-type stars that fulfill
our selection criteria, EPIC 202059229 and EPIC 245919787, were analyzed in
more detail. We found that for both stars the rotation period did not change
while the rotational phase did change for EPIC 245919787 by ~0.2. The amplitude
of the spot induced variability changed for both stars but more significant for
EPIC 245919787. By comparing the cumulative flare frequency distributions we
found that the flare activity for EPIC 202059229 is unchanged while it slightly
changes for EPIC 245919787 between the K2 and TESS epochs. Using a combination
of light curves from K2 and TESS that span a baseline up to 4.5 years we could
measure significant differential rotation for EPIC 245919787. Furthermore, we
show that combining missions like K2 and TESS is a promising method for
detecting stellar activity cycles.
