Tenth house is known as the placement for judging one's type and level of success in career's life as its called karma sthana. Tenth house is the strongest among houses in the chart and its strength and auspiciousness guarantees professional luck in life. However Jyotisha classics suggest seeing tenth bhava both from lagna and Chandra (moon). And the latter becomes more important for general success as it shows support one's get from the society for the career life. According to Saravali and Brhat Jataka Navamsa Rasi of the tenth lord from Lagna would show type of job or article associated with work. There are much more points to check in the Rasi and Dasamsa - to list a few : hora lagna, varnada lagna, yogada, amatyakaraka, ghatika lagna, karma nakshatra etc. - before arriving at the proper conclusion related to type and amount of success coming from work. Tenth lord from Chandra when afflicted is sure combination for challenges and misfortunes in overall career life.
Timing new job
Whilst timing getting new job, first Rasi Chart should be analyzed to grasp general availability and situation followed by the Dasamsa analysis in which we get clearer picture of work-surrounding.
General rule is that Mahadasa should have argala to the forth house from Surya in Dasamsa to give job availability. Antardasa graha should have yoga with the fifth lord or unobstructed argala to it, whilst Pratyantar dasa graha (Vidasha) should have yuti or drsti on fifth lord. These grahas should be also well-placed from Lagnesh (especially Mahadasa graha is judged both from Lagnesh, Surya and Atmakaraka), otherwise due to uncomfortable situation one will not reach or reject the opportunity.
Rasi chart should have Rahu connected to Amatyakaraka (pointing at Surya) to guarantee government job. People whose work is associated with government service should have luminaries influencing artha -trikona in Dasamsa with the sixth house being stronger indicating service (instead of business indicated by the seventh house).
Ref : Rafal Gendarz's post on Srijagannath