lane a Alice
lane b Bob\n(Server)

call - > a Wakeup
start a
call a > a Check
send a > b REQUEST id=123\ncontents={Date, Time}
start b
end a

hline 1. GetDate Section

lane c Carol\n(Date provider)
call b > c GetDate locale=jpn
start c
return b < c date='1999/12/31'
end c

hline 2. GetTime Section

lane d Dave\n(Time provider)
call b > d GetTime type=24h
start d
return b < d time='23:59:59'
end d

send a < b REPLY datetime='1999/12/31 23:59:59'
start a
end b
end a