For eight months, Dong Yan, 49, did not take a single weekend off. Her goal was simple yet challenging: to brighten Hangzhou's West Lake for the upcoming G20 Summit.

Anyone who happened to visit the lake at night last year would definitely notice that the southern shore was in virtual darkness - a fact made even starker by the color glow on the north shore and the city skyline to the east.

Dong's mission was to bring light to the dark side. As head of the construction department at Huagang administrative office, one of eight administrative divisions that manage the West Lake area, Dong got orders about 17 months ago to make the lake shine for the G20 Summit, which falls on Sept 4 and 5. For some, especially those in charge of the northern areas, the job might involve changing some existing light bulbs or installing some new fancy effects. For Dong and her colleagues, however, it meant building everything from scratch.

After public bidding, construction officially began in November. Dong and her colleagues spent countless days and nights with construction workers to make sure everything was done right, and on time.

"I think there is no standard for our G20 project," she said. "Only when the residents and visitors all feel satisfied can we say the project is successful. Because of that, I've put myself under a lot of pressure."

But don't let her slight frame fool you: Dong is tough. The chief of the Huagang office, Ding Gaofeng, said he had seen many times when Dong visited a hospital in the morning and then rushed back to construction sites in the afternoon. He seldom saw her take a break.

"There was too much to do. I cannot afford to be sick," Dong said. "How many big projects like this can I work on in my lifetime? This will probably be the last milestone in my career. I must leave no regrets."

Dong's team was the only one that kept working through the Spring Festival, China's lunar new year. When last winter's snow blocked mules from carrying equipment to the mountains, Dong and her colleagues loaded gear onto their own shoulders and continued climbing. Their overtime work meant the project would be finished in mid-March, more than a month ahead of schedule.

Since then, all the Huagang staff has joined a rigorous work rotation to fill shifts 24 hours a day, seven days a week. Their task is to make sure all glitches are identified and fixed. A daily test run of the lights that lasts from 6 pm to 10:30 pm has been going on for about five months. No major problem was found.

Before the summit, West Lake kept most its lights turned off from Monday to Thursday. They only came alive on weekend nights and holidays.

The specific arrangement of the lights after the G20 is still under discussion, according to Ding.

Social media photo posts depicting the West Lake lights have been going viral on major social media platforms in China, including Weibo and WeChat. Residents and tourists are seen waiting in long lines after supper every day outside various entrances to see the newly brightened West Lake.