This question is never asked about the creation of the Sri Guru Granth Sahib, and as Sri Dasam Granth is the work of Guru Gobind Singh Ji this is also insulting. However there are no internal dates within Sri Guru Granth Sahib but there are some dates of creation of different compositions/works within Sri Dasam Granth. As Sri Dasam Granth is mainly placing Sikhism in a historical context these dates are important. Some of these dates are as follows:
ਸੱਤਰਸੈਪੈਤਾਲ ਿਮਹ ਸਾਵਨ ਸੁਿਦ ਿਥਿਤ ਦੀਪ ॥ ਨਗਰ ਪਵਟਾ ਸੁਭ ਕਰਨ ਜਮਨਾ ਬਹੈਸਮੀਪ ॥2490॥
(This work has been completed) in the year 1745 of the Vikrami era in the Sudi aspect
of the moon in the month of Sawan, (July 1688 A.D.) in the town of Paonta at the
auspicious hour, on banks of the flowing Yamuna.
(Sri Guru Gobind Singh Sahib in ‘Krishnavtar’)
ਸੰਬਤ ਸਤਰਸਹਸ ਿਭਣਜੈ॥ ਅਰਧ ਸਹਸ ਫੁਿਨ ਤੀਿਨ ਿਕਹਜੈ॥ ਭਾਦਰ ਸੁਦੀ ਅਸਟਮੀ ਿਰਵ ਵਾਰਾ ॥
ਸਤੁਦਰ ਗ!ੰਥ ਸੁਧਾਰਾ ॥405॥
This (work) was completed on Sunday, the 18th day of month of Bhadon, in 1753
Bikrami Sammat (September 14, 1696 A.D.) on the banks of river Satluj.
(Sri Guru Gobind Singh Sahib in ‘Charitropakhyan’)
ਸੰਮਤ ਸੱਤਰਸਹਸ ਪਚਾਵਨ॥ ਹਾੜ ਵਦੀ ਿਪ!ਥਮੈਸੁਖ ਦਾਵਨ ॥ ਤ ਪ!ਸਾਿਦ ਕਿਰ ਗ!ੰਥ ਸੁਧਾਰਾ ॥ ਭੂਲ ਪਰੀ
This Granth has been completed (and improved) in Vadi first in the month of Haar in
the year 1755 Bikrami (July 1698); if there has remained any error in it, then kindly
(Sri Guru Gobind Singh Sahib in ‘Ramavtaar’)